Instrument Panel - Standard & Electronic GMC Value Van P3500

All Models

Standard mechanical instrument clusters on all models except "S" series are designed to permit the removal and installation of all control switches and illuminating bulbs from the driver's side. The standard instrument clusters are equipped with warning lights. Optional instrument clusters come equipped with gauges, as well as warning lights.

Astro, Safari & "S" Series

The electronic instrument cluster is a solid-state device that uses a digital display to transmit information to driver. The electronic instrument cluster receives signals from several components and systems on vehicle.

The electronic instrument cluster receives input signals from: English/Metric switch, odometer trip switch, battery, odometer reset switch, ignition, lighting system, oil sending unit, fuel sending unit, charging system, temperature sending unit, and the digital ratio adapter controller.

The vehicle speed sensor signal originates at transmission, and is changed to a digital signal by the digital ratio adapter controller. The electronic instrument cluster does not contain any serviceable components and is serviced as an assembly.

Astro, "C", "K" & "S" Series & Safari

The speedometer/odometer used with a standard instrument cluster is an electronic speedometer (electromechanical on "C", "K" and "S" series). Integrated circuits control the air-core speedometer and stepper motor odometer. The speedometer and odometer receive a signal from buffer or Digital Ratio Adapter Controller (DRAC), which received its input from vehicle speed sensor.

"G", "P", "R" & "V" Series

The speedometer is a mechanical type unit that is driven by a cased cable which is connected to transmission.

The Digital Ratio Adapter Controller (DRAC), or Digital Ratio Adapter (DRA) on "C" and "K" series, is a solid-state device that is used to change the signal from the vehicle speed sensor to a digital signal for speedometer operation.

The DRAC (DRA) is matched to the final drive ratio of each vehicle. If the final drive ratio is changed for any reason, the DRAC (DRA) must be changed on Astro, "S" series and Safari (recalibrated on "C" and "K" series) to maintain accurate speedometer/odometer reading. Incorrect DRAC (DRA) calibration will also affect Rear Wheel Anti-Lock (RWAL), Electronic Control Module (ECM), and cruise control module.

The Vehicle Speed Sensor (VSS) is a permanent magnet signal generator located on transmission output shaft housing. A toothed rotor rotates near a coil producing voltage pulses that are sent to the DRAC or buffer.

The pointer in fuel gauge is moved by the magnetic field of 2 coils. The coils are at right angles to each other. Battery voltage is applied to the empty coil and the circuit is divided at the opposite end of the coil. One path continues to ground through the full coil, while other path goes to ground through the fuel gauge sending unit (a variable resistor) in fuel tank.

When fuel level in tank is low, the fuel gauge sending unit resistance is low. A large flow of current passes through the empty coil and the fuel gauge sending unit resistor. This moves fuel gauge pointer to toward the "E" (empty) position.

When fuel level in tank is high, the fuel gauge sending unit resistance is high. More current now flows through the full coil, moving the fuel gauge pointer toward the "F" (full) position. With 2 coils operating pointer, the fuel gauge is not affected by changes in battery voltage.

The coolant temperature gauge is also operated by 2 coils. One coil is directly grounded and the other is grounded through the coolant temperature sending unit. The sending unit has a resistance of 55 ohms at 260°F (127°C) and a resistance of 1400 ohms at 100°F (38°C). As coolant temperature increases, current flow through sending unit and one coil increases, causing pointer to move.

The oil pressure gauge pointer is moved by 2 coils. Its operation is similar to that of fuel gauge. The oil pressure sending unit is connected to the junction of the 2 coils. The sending unit has a low resistance when oil pressure is low and a resistance of 90 ohms when oil pressure is high. A change in resistance changes current flow through field coils, causing pointer to move from low to high.

The voltmeter measures voltage of charging system. On Astro and Safari, the voltmeter uses an internal shunt and is connected to Black wire (terminal No. 11) and Pink/Black wire (terminal No. 17) of connector No 1.

The oil pressure warning system consists of an oil pressure switch and a warning light on instrument cluster. The oil pressure switch closes when oil pressure drops below 4 psi (.28 kg/cm 2 ).

The coolant temperature warning system consists of temperature switch and warning light on instrument cluster. When coolant overheats, the switch closes and the warning light comes on. The switch closes when coolant temperature reaches 257°F (125°C).

The charging system warning system consists of a warning light with one side of bulb connected to alternator and the other side of bulb connected to battery. If a charging system malfunction is detected, the warning light will come on.

The brake warning system consists of a differential switch on brake combination valve and warning light on instrument cluster. If a hydraulic malfunction is detected, the warning light will come on.

"C", "K" & "S" Series

This optional warning light comes on when engine coolant temperature is too high or when engine oil pressure is too low. The signals from the engine coolant temperature and oil pressure sending units are monitored by the "CHECK GAGES" light driver. The light driver is an integral part of the temperature gauge circuit board.

SPEEDOMETER CALIBRATION

Note. Do not touch pins at back of instrument cluster as immediate damage to cluster will occur. The DRAC must be replaced or recalibrated when rear axle ratio or tire size is changed.

"C" & "K" Series

1. Remove instrument cluster from vehicle. Plug connector from service kit into back of instrument cluster and momentarily touch the wires across the vehicle battery terminals. NOTE: The connector from service kit should be used a maximum of 10 times. It is not necessary to perform step 1) if speedometer has been previously recalibrated. Follow specific instructions provided with service kit.
2. Check «INSTRUMENT PANEL CALIBRATION SPECIFICATIONS»(/gmc/value-van-p3500/1985-1993/remont/gauges-instrument-panels/#instrument-panel-standard-electronic__instrument-panel-calibration-specifications-scheme-8) using vehicle axle ratio and corresponding tire size to find the appropriate pins to be removed from clip. The rectangular end of clip is at the top. The pins are numbered 1 through 8 from top to bottom. (Scheme 1)
3. Remove pins by bending them back and forth with long needle nose pliers. Insert modified clip into 8 holes in rectangular slot on back of instrument cluster. Install instrument cluster in vehicle.

Scheme 1

FUEL GAUGE

Note. If vehicle is equipped with electronic fuel gauge, Refer to ELECTRONIC INSTRUMENT CLUSTER TEST in this article.

Scheme 2

1. If gauge constantly reads "E" (empty), go to next step. If gauge constantly reads "F" (full), go to step 4). If gauge reading is inaccurate, go to step 6).
2. Check for fuel in tank. If empty, fill tank with fuel. If gauge continues to indicate "E" (empty), check for a grounded fuel gauge circuit by disconnecting lead at fuel tank.
3. Fuel gauge should now read past "F" (full) mark. If gauge does not read past "F" (full) mark, replace fuel gauge sending unit. If gauge still reads "E" (empty), find short to ground between gauge and fuel tank.
4. If gauge reads "F" (full), check for an open circuit between gauge and sending unit by disconnecting sending lead at fuel tank. Connect lead to ground and note reading on gauge.
5. If fuel gauge reads "E" (empty), replace fuel gauge sending unit. If fuel gauge still reads "F" (full) or beyond, find open wire between gauge and fuel tank.
6. If gauge reading is inaccurate, check wiring for corroded or loose connections. Clean and tighten as required. If okay, remove fuel gauge sending unit. Using an ohmmeter, test sending unit resistance. See «FUEL GAUGE SENDING UNIT RESISTANCE»(/gmc/value-van-p3500/1985-1993/remont/gauges-instrument-panels/#instrument-panel-standard-electronic) table.
7. If sending unit values are correct, disconnect front body connector. Connect Gauge Tester (J-24538-A) to lead that goes to gauge. Turn ignition on. If gauge reads accurately, check wiring between rear compartment and front connector.
8. If gauge reads between 1/4 and 1/2 full with tester set at 90 ohms, remove gauge and check for loose nuts at gauge terminals. If nuts are tight and gauge still reads inaccurately, replace fuel gauge.

FUEL GAUGE SENDING UNIT RESISTANCE

Scheme 3

1. Disconnect fuel gauge sender wire and connect Gauge Tester (J-24538-A) between sender wire and ground. Turn ignition on. If gauge responds, but not accurately, go to next step. If gauge does not respond, go to step 3). If gauge responds accurately, go to step 5).
2. Remove gauge and check for loose nuts at gauge terminals. If nuts are loose and gauge reads between 1/4 and 1/2 with 90 ohms from tester, tighten nuts and install gauge. If gauge is still inaccurate and nuts are tight, replace gauge.
3. Disconnect front body connector. Connect tester to lead that goes to gauge. If gauge responds accurately, check wiring between rear compartment and front body connector. If gauge does not respond, go to next step.
4. Remove gauge. Check for bad connections at gauge terminals or instrument cluster connector. If connections are good, replace gauge. If bad, repair connections and install gauge.
5. Check rear compartment connector and wiring to sender. If okay, replace sender. If not okay, repair wire or connector.

OIL PRESSURE GAUGE

Note. If vehicle is equipped with electronic oil pressure gauge, See ELECTRONIC INSTRUMENT CLUSTER TEST in this article.

1. If gauge constantly reads "0" psi, go to next step. If gauge constantly reads "80" psi or above, go to step 4). If gauge reading is inaccurate, go to step 6).
2. Check oil level. Add oil if necessary. If gauge continues to indicate "0" psi, check for a grounded oil pressure gauge circuit by disconnecting lead at sending unit.
3. Oil pressure gauge should now read "80" psi. If gauge stays at "0" psi, disconnect lead from gauge. Oil pressure gauge should now read "80" psi. If correct, find short to ground between gauge and sending unit. If gauge reads "0" psi, replace gauge and test oil pressure gauge sending unit resistance. Refer to, in this article, «OIL PRESSURE GAUGE SENDING UNIT RESISTANCE»(/gmc/value-van-p3500/1985-1993/remont/gauges-instrument-panels/#instrument-panel-standard-electronic) table. Replace sending unit if it reads one ohm with engine running.
4. If gauge reads "80" psi or above, check for an open circuit between gauge and sending unit by disconnecting lead at sending unit. Connect lead to ground and note reading on gauge.
5. If oil pressure gauge reads "0" psi, replace oil pressure gauge sending unit. If oil pressure gauge still reads "80" psi or beyond, find open wire between gauge and sending unit.
6. If gauge readings are inaccurate, disconnect lead from oil pressure sending unit. Connect Gauge Tester (J24538-A) to lead and ground. Turn ignition on. If gauge reads accurately, replace oil pressure sending unit. If gauge still reads inaccurately, replace oil pressure gauge.

OIL PRESSURE GAUGE SENDING UNIT RESISTANCE

1. Disconnect oil pressure gauge sender wire and connect Gauge Tester (J-24538-A) between sender wire and ground. Turn ignition on. If gauge responds to tester accurately, replace sender. If gauge does not respond, go to next step. If gauge responds, but not accurately, go to step 4).
2. Disconnect oil pressure gauge lead at engine harness connector. Connect tester to lead that goes to gauge. If gauge responds to tester accurately, check wiring between sender connector and engine harness connector. If gauge does not respond, go to next step.
3. Remove gauge. Check for bad connections at gauge terminals or instrument cluster connector. If connections are good, replace gauge. If bad, repair connections and install gauge.
4. Remove gauge and check for loose nuts at gauge terminals. If nuts are loose and gauge reads slightly below mid-scale with 90 ohms from tester, tighten nuts and install gauge. If gauge is still inaccurate and nuts are tight, replace gauge.

If warning light does not come on (engine off, switch on), check for burned out light bulb. Replace bulb if necessary. If bulb is okay, check for an open in circuit. To do so, remove lead from oil pressure switch and ground lead. If warning light does not come on, find open in circuit. If light comes on, replace switch.

COOLANT TEMPERATURE GAUGE

Note. If vehicle is equipped with electronic coolant temperature gauge, See ELECTRONIC INSTRUMENT CLUSTER TEST in this article.

Astro & Safari

1. If gauge reads "COLD" when engine is hot, go to next step. If gauge reads "HOT" when engine is cold, go to step 5). If gauge readings are too low, go to step 7). If gauge readings are too high, go to step 8).
2. Check for blown fuse and replace if necessary. If fuse is okay, disconnect lead from sending unit and turn ignition on. Connect a test light between lead and ground. If test light glows, go to next step. If not, go to step 4).
3. Connect lead to a known good ground. If temperature gauge reads "HOT", check lead connector on sending unit. If okay, replace sending unit. If gauge still reads "COLD", replace temperature gauge.
4. If test light did not glow, check continuity between sending unit terminal at gauge and ground, and between ignition terminal and ground. Also check temperature gauge case ground. If all checks are okay, replace temperature gauge.
5. If gauge constantly reads "HOT", remove lead from temperature gauge sending unit. Gauge reading should go to "COLD". If gauge reading does not swing to "COLD", check sending unit for an external short. If there is no external short, replace sending unit.
6. If temperature gauge continues to read "HOT" after replacing sending unit, check for short circuit in wiring between sending unit and gauge. If no short exists, replace temperature gauge.
7. If readings are inaccurate, check wiring for corroded or loose connections. If necessary, clean and tighten terminals and connections. Also check resistance in temperature sending unit ground circuit. If terminals connections and ground circuit are okay, go to next step.
8. Disconnect lead from temperature gauge sending unit. Using an ohmmeter, test sending unit resistance. See «TEMPERATURE GAUGE SENDING UNIT RESISTANCE»(/gmc/value-van-p3500/1985-1993/remont/gauges-instrument-panels/#instrument-panel-standard-electronic) table. If sending unit values are incorrect, replace temperature gauge sending unit.

TEMPERATURE GAUGE SENDING UNIT RESISTANCE

1. If gauge reads "100" when engine is hot, go to next step. If gauge reads "260" when engine is cold, go to step 5). If gauge readings are too low, go to step 7). If gauge readings are too high, go to step 8).
2. Check for blown fuse and replace if necessary. If fuse is okay, disconnect lead from sending unit and turn ignition on. Connect a test light between lead and ground. Gauge should indicate "260". If test light glows, go to next step. If not, go to step 4).
3. Connect lead to a known good ground. If temperature gauge reads "100", check lead connector on sending unit. If okay, replace sending unit. If gauge still reads "100", replace temperature gauge.
4. If test light did not glow, check continuity between sending unit terminal at gauge and ground, and between ignition terminal and ground. Also check temperature gauge case ground. If all checks are okay, replace temperature gauge.
5. If gauge constantly reads "260", remove lead from temperature gauge sending unit. If gauge does not swing to "100", check sending unit for an external short. If there is no external short, replace sending unit.
6. If temperature gauge continues to read "260", check for short circuit in wiring between sending unit and gauge. If no short exists, replace temperature gauge.
7. If readings are inaccurate, check wiring for corroded or loose connections. If necessary, clean and tighten terminals and connections. Also check resistance in temperature sending unit ground circuit. If terminals connections and ground circuit are okay, go to next step.
8. Disconnect lead from temperature gauge sending unit. Using an ohmmeter, test sending unit resistance. See «TEMPERATURE GAUGE SENDING UNIT RESISTANCE»(/gmc/value-van-p3500/1985-1993/remont/gauges-instrument-panels/#instrument-panel-standard-electronic) table. If sending unit values are incorrect, replace temperature gauge sending unit.

1. Disconnect temperature gauge sender wire and connect Gauge Tester (J-24538-A) between sender wire and ground. Turn ignition on. If gauge responds to tester accurately, replace sender. If gauge does not respond or is inaccurate, go to next step. If gauge responds well beyond "HOT", go to step 4).
2. Disconnect temperature gauge lead at engine harness connector. Connect tester to lead that goes to gauge. If gauge responds to tester accurately, check wiring between sender connector and engine harness connector. If gauge does not respond, go to step 3).
3. Remove gauge. Check for bad connections at gauge terminals or instrument cluster connector. If connections are good, replace gauge. If bad, repair connections and install gauge.
4. Remove gauge and check for loose nuts at gauge terminals or lack of ground connection to gauge. If connections are good, replace gauge. If connections are bad, repair connections and install gauge.

If warning light does not come on during bulb check, check for burned out light bulb. Replace bulb if necessary. If bulb is okay, check for an open in circuit. To do so, remove lead from coolant temperature switch and ground lead. If warning light does not come on, find open in circuit. If light comes on, replace switch.

Scheme 4

VOLTMETER

Note. If vehicle is equipped with electronic voltmeter, refer to ELECTRONIC INSTRUMENT CLUSTER TEST in this article.

1. Measure voltage across battery terminals. If battery is discharged, find and correct cause of discharged battery.
2. Recharge battery. With key in "ON" position and battery terminals connected, observe voltmeter with battery charger in operation. The voltmeter should come up to at least 12 volts. If not, check for high resistance in voltmeter connections. Clean and tighten connections.
3. If voltmeter reading is still low, apply 12 volts directly to positive terminal of voltmeter. If voltmeter does not respond accurately, it must be replaced.

1. If "CHECK GAGES" light does not come on with high temperature, go to next step. If "CHECK GAGES" does not light with low oil pressure, go to step 3). If "CHECK GAGES" light is on all times, go to step 4).
2. Check for burned out "CHECK GAGES" bulb. Replace bulb if necessary. Check for inoperative temperature gauge circuit. Replace temperature gauge if necessary. If temperature gauge circuit is okay, replace defective instrument cluster.
3. Check for burned out "CHECK GAGES" bulb. Replace bulb if necessary. Check for inoperative oil pressure gauge circuit. Replace oil pressure gauge if necessary. If oil pressure gauge circuit is okay, replace defective instrument cluster.
4. Check for inoperative temperature and oil pressure gauge circuits. Replace temperature and/or oil pressure gauge if necessary. If temperature and oil pressure gauge circuits are okay, replace defective instrument cluster.

See VEHICLE SPEED SENSOR & DIGITAL RATIO ADAPTER/CONTROLLER , in this article.

1. Check rear axle ratio and rear tire size. If rear axle ratio and tire size are the same as when vehicle was manufactured, check vehicle speed sensor circuit. See «VEHICLE SPEED SENSOR TEST»(/gmc/value-van-p3500/1985-1993/remont/gauges-instrument-panels/#instrument-panel-standard-electronic) in this article.
2. If rear axle ratio and/or tire size are different than when vehicle was manufactured, check digital ratio adapter programming clip. See «INSTRUMENT PANEL CALIBRATION SPECIFICATIONS»(/gmc/value-van-p3500/1985-1993/remont/gauges-instrument-panels/#instrument-panel-standard-electronic__instrument-panel-calibration-specifications-scheme-8) at end of this article.
3. Check for brake Code 9 and inoperative speedometer/odometer or ECM Code 24 with correctly operating speedometer/odometer. If ECM code 24 is set and speedometer/odometer operate, check vehicle speed sensor buffer output. See, in this article «BUFFER OUTPUT DIAGNOSIS»(/gmc/value-van-p3500/1985-1993/remont/gauges-instrument-panels/#instrument-panel-standard-electronic__buffer-output-diagnosis) .
4. If brake Code 9 is set and speedometer/odometer are inoperative, check vehicle speed sensor buffer power input. See, in this article, «BUFFER POWER DIAGNOSIS»(/gmc/value-van-p3500/1985-1993/remont/gauges-instrument-panels/#instrument-panel-standard-electronic__buffer-power-diagnosis) . Also check vehicle speed sensor circuit. See «VEHICLE SPEED SENSOR TEST»(/gmc/value-van-p3500/1985-1993/remont/gauges-instrument-panels/#instrument-panel-standard-electronic) in this article.

1. If speedometer is noisy or sticky, check for kinked, pinched or burnt casings. Check for bent cable tips, improper or insufficient lubrication of cable, or rough drive gear.
2. If speedometer whines, driven gear stem in transmission could be binding with adapter. If calibration is incorrect, possible causes include incorrect transmission adapter, incorrect drive gear or sleeve, over or undersize tires, and faulty speedometer head.

Scheme 5

1. Disconnect vehicle speed sensor at transmission and check sensor resistance. If resistance is between 900-2000 ohms, reconnect harness and go to step 2). If resistance is incorrect, replace vehicle speed sensor and retest speedometer/odometer operation.
2. Raise and support rear of vehicle. Disconnect instrument cluster connector. Start engine and place transmission in Drive. Using a digital volt/ohmmeter, check for AC voltage between Yellow wire (terminal "B13") and Purple wire (terminal "B16").
3. If AC voltage varies with driveshaft RPM, vehicle speed sensor is okay. If no AC voltage is detected, check wires for open circuits and connectors for tightness. If wiring and connectors are okay, replace vehicle speed sensor.

If speedometer and odometer are inaccurate, ensure that correct Digital Ratio Adapter Controller (DRAC) is installed. If speedometer and odometer do not operate properly, perform the following test(s).

DRAC Inoperative

Disconnect DRAC and turn ignition switch to "RUN" position. Check for voltage between Pink/Black wire in harness and a known good ground. If voltage is less than battery voltage, check for an open or short in Pink/Black wire.

Poor Ground Path

Check for voltage between Pink/Black wire (Lt. Blue/Black wire on "S" series) in DRAC harness and Black/White wire (Black wire on "S" series). If voltage is less than battery voltage, check for an open or short in Black/White (Black wire on "S" series) wire.

No Vehicle Speed Sensor Signal

1. Raise and support vehicle. Start engine and place transmission in Drive. Check vehicle speed sensor AC voltage between Purple/White wire and Light Green/Black wire at digital ratio adapter controller. Voltage should change as engine RPM is decreased and increased.
2. If there is no vehicle speed sensor AC voltage at these wires, check for an open or short in both wires. If no open or short is found in wires, replace vehicle speed sensor.

No Speedometer Output

Raise and support vehicle. Start engine and place transmission in drive. With connector attached, check for varying AC voltage between Light Blue/Black wire and Black/White wire (Black wire on "S" series) at digital ratio adapter controller. If voltage varies with engine RPM, replace DRAC.

No Cruise Control Output

Raise and support vehicle. Start engine and place transmission in drive. With connector attached, check for varying AC voltage between Yellow wire and Black/White wire (Black wire on "S" series) at DRAC. If voltage varies with engine RPM, replace DRAC.

Inoperative Speedometer Or Odometer

See ELECTRONIC INSTRUMENT CLUSTER TEST in this article.

Check that DRA programming clip is installed in DRA, and that has the proper pins removed. See INSTRUMENT PANEL CALIBRATION SPECIFICATIONS at end of article.

BUFFER OUTPUT DIAGNOSIS

Note. The buffer output diagnosis is to be performed only after SPEEDOMETER/ODOMETER diagnosis has been performed.

1. Disconnect instrument cluster connector. Place ignition switch in the "RUN" position. Check for 12 volts between ground and Brown wire at terminal "A16". If reading is less than 12 volts, check for an open circuit in Brown wire.
2. If reading is 12 volts, check for 12 volts between ground and Brown/White wire at terminal "B17" If reading is 12 volts, replace instrument cluster. If reading is less than 12 volts, check for an open circuit in Brown/White wire. It may be necessary to enter ECM diagnostics. See COMPUTERIZED ENGINE CONTROLS section.

BUFFER POWER DIAGNOSIS

Note. The buffer power diagnosis is to be performed only after SPEEDOMETER/ODOMETER diagnosis has been performed.

1. Disconnect instrument cluster connector. Place ignition switch in the "RUN" position. Check for 12 volts between ground and Pink/Black wire at terminal "A10". If reading is 12 volts, go to next step. If reading is less than 12 volts, check gauges fuse. Replace fuse if necessary. If fuse is okay, check for short or open in Pink/Black wire.
2. Check for 12 volts between ground and Brown/White wire at terminal "B14". If reading is 12 volts, go to next step. If reading is less than 12 volts, check speedometer fuse. Replace fuse if necessary. Check for short or open in Brown/White wire.
3. Check for 12 volts between Brown/White wire (terminal "B14") and Black/White wire (terminal "B15"). If reading is 12 volts, go to next step. If reading is less than 12 volts, check for open in Black/White wire.
4. Check for 12 volts between Brown/White wire (terminal "B14") and Black wire (terminal "B1"). If reading is 12 volts, check vehicle speed sensor circuit. See «VEHICLE SPEED SENSOR TEST»(/gmc/value-van-p3500/1985-1993/remont/gauges-instrument-panels/#instrument-panel-standard-electronic) in this article. If reading is less than 12 volts, check for open in Black wire.

Cluster Display Does Not Light (Astro & Safari)

1. Check for ignition feed to cluster, ground, and for an inoperative cluster. To do so, disconnect large 17-pin connector from cluster.
2. Using a digital volt/ohmmeter, measure voltage from pin No. 13 to ground with ignition switch in "RUN" position. Battery voltage should exist. If okay, go to next step. If meter reads less than battery voltage or zero, repair Pink/White wire from ignition. (Scheme 2)
3. Using a digital volt/ohmmeter, measure resistance from pins No. 15 and 16 to ground. If meter reads anything but 0-0.5 ohms, repair Black wires at pins No. 15 and 16 to ground. If resistance is correct, go to next step.
4. If ignition feed and ground circuits are okay, replace inoperative instrument cluster.

Cluster Display Does Not Light ("S" Series)

1. Check for ignition feed to cluster, and for an inoperative cluster. To do so, disconnect large 34-pin connector from cluster. Using a digital volt/ohmmeter, measure voltage from pin "A15" to pin "B7" with ignition switch in "RUN" position. (Scheme 2)
2. Digital volt/ohmmeter should read battery voltage. If meter reads less than battery voltage or zero, repair Pink/White wire from ignition. If ignition feed circuit is okay, replace inoperative instrument cluster.

Cluster Display Does Not Dim With Lights On (Astro & Safari)

1. Check for open or shorted parking light feed, bad parking light switch, and for an inoperative cluster. To do so, turn parking lights on and place ignition switch in "RUN" position.
2. Using a digital volt/ohmmeter, measure voltage between ground and pin No. 8 of large 17-pin connector. If reading is less than battery voltage, repair open or short in Brown wire. If reading is okay, go to next step.
3. With parking lights on and ignition switch in "RUN" position, use digital volt/ohmmeter to measure voltage between ground and pin No. 7 of large 17-pin connector. Adjust panel light dimmer switch from high intensity to low intensity.
4. Voltmeter should read between zero (0) and battery voltage. If this reading is not obtained, repair Gray wire and/or parking light switch. If above steps are okay, replace inoperative instrument cluster.

Cluster Display Does Not Dim With Lights On ("S" Series)

1. Check for open or shorted parking light feed, bad parking light switch, and for an inoperative cluster. To do so, turn parking lights on and place ignition switch in "RUN" position.
2. Using a digital volt/ohmmeter, measure voltage between ground and pin "A6" of large 34-pin connector. If reading is less than battery voltage, repair open or short in Brown wire. If reading is okay, go to next step.
3. With parking lights on and ignition switch in "RUN" position, use digital volt/ohmmeter to measure voltage between ground and pin "A6" of large 17-pin connector. Adjust panel light dimmer switch from high intensity to low intensity.
4. Voltmeter should read between zero (0) and battery voltage. If this reading is not obtained, repair Brown wire and/or parking light switch. If above steps are okay, replace inoperative instrument cluster.

Cluster Display Always Dim (Astro, Safari & "S" Series)

Replace inoperative instrument cluster.

Cluster Display Does Not Switch Between English & Metric (Astro & Safari)

1. Check for inoperative cluster controls switch, wiring, or inoperative cluster. To do so, disconnect large 17-pin connector at cluster. Measure cluster control switch resistance between pin No. 2 and ground.
2. Resistance should be zero (0) in one position, and open in the other. If switch does not respond as indicated, repair Light Blue wire between cluster and switch, the switch, or the Black wire from switch to ground.
3. If switch and related wiring are okay, replace inoperative instrument cluster.

Speedometer Inoperative Or Inaccurate, Odometer Operates Correctly (Astro, Safari & "S" Series)

Replace inoperative instrument cluster.

One or Both Odometers Do Not Operate Properly, Speedometer Operates Properly (Astro, Safari & "S" Series)

Replace inoperative instrument cluster.

Speedometer & Odometer Do Not Operate (Astro, Safari & "S" Series)

1. Check for vehicle speed sensor signal. To do so, disconnect large 17-pin connector (34-pin connector on "S" series) from cluster and the Digital Ratio Adapter Controller (DRAC) connector.
2. Measure resistance between wire at pin No. 1 ("A11" on "S" series) of cluster and wire at pin "B" of DRAC harness. If resistance is above zero (0) ohms, and the vehicle speed sensor circuit is working properly, replace inoperative instrument cluster.

Cluster Display Does Not Switch Between Total & Trip Odometer (Astro & Safari)

1. Check for an inoperative cluster control switch or wiring. To do so, disconnect large 17-pin connector from cluster. Measure resistance between pin No. 3 and ground.
2. Resistance should be zero (0) in one position, and open in the other. If switch does not respond as indicated, repair Light Green wire between cluster and switch, the switch, or the Black wire from switch to ground.
3. If switch and related wiring are okay, replace inoperative instrument cluster.

Trip Odometer Does Not Reset (Astro & Safari)

1. Check for an inoperative cluster control switch or wiring. To do so, disconnect large 17-pin connector from cluster. Measure resistance between pin No. 5 and ground.
2. Resistance should be zero (0) in one position, and open in the other. If switch does not respond as indicated, repair Light Green/Black wire between cluster and switch, the switch, or the Black wire from switch to ground.
3. If switch and related wiring are okay, replace inoperative instrument cluster.

Fuel Gauge Is Inaccurate (Astro, Safari & "S" Series)

1. Check for shorts or opens in wiring between fuel tank sending unit and cluster, or for an inoperative fuel tank sending unit. To do so, disconnect fuel gauge sending unit at fuel tank. Connect one lead of Instrument Panel Tester (J-33431) to Pink wire and other lead to ground.
2. Turn ignition switch to "RUN" position and set tester resistance dials to zero (0) ohms. Fuel gauge should read empty. Now set resistance dials to 35 ohms. Fuel gauge should have 7-8 segments lit (half full). Finally, set resistance dials to 90 ohms. Fuel gauge should read full.
3. If fuel gauge responds correctly, check Black wire to ground at fuel gauge sending unit. If Black wire is okay, replace fuel gauge sending unit. If gauge does not respond as indicated, check Pink wire between fuel gauge sending unit and cluster. If wire is okay, replace inoperative cluster.

Low Fuel Indicator Does Not Light With Low Fuel Level (Astro, Safari & "S" Series)

Replace inoperative instrument cluster.

Temperature Gauge Is Inaccurate (Astro, Safari & "S" Series)

1. Check for shorts or opens in wiring between temperature sending unit and cluster, or for an inoperative temperature sending unit. To do so, disconnect temperature sending unit at engine. Connect one lead of Instrument Panel Tester (J-33431) to Dark Green wire and other lead to ground.
2. Turn ignition switch to "RUN" position and set tester resistance dials to 1400 ohms. Temperature gauge should read cold. Now set resistance dials to 400 ohms. Temperature gauge should have 7-8 segments lit. Finally, set resistance dials to zero (0) ohms (55 ohms on "S" series). Temperature gauge should read hot.
3. If temperature gauge responds correctly, replace temperature gauge sending unit. If gauge does not respond as indicated, check Dark Green wire between temperature gauge sending unit and cluster. If wire is okay, replace inoperative cluster.

Temperature Indicator Does Not Light With Engine Coolant Overheated (Astro, Safari & "S" Series)

Replace inoperative instrument cluster.

Oil Pressure Gauge Inaccurate (Astro, Safari & "S" Series)

1. Check for shorts or opens in wiring between oil pressure sending unit and cluster, or for an inoperative oil pressure sending unit. To do so, disconnect oil pressure sending unit at engine. Connect one lead of Instrument Panel Tester (J-33431) to Tan wire and other lead to ground.
2. Turn ignition switch to "RUN" position and set tester resistance dials to zero (0) ohms. Oil pressure should read low. Now set resistance dials to 35 ohms. Oil pressure gauge should have 7-8 segments lit. Finally, set resistance dials to 90 ohms. Oil pressure gauge should read high.
3. If fuel gauge responds correctly, replace oil pressure gauge sending unit. If gauge does not respond as indicated, check Tan wire between fuel gauge sending unit and cluster. If wire is okay, replace inoperative cluster.

Oil Pressure Indicator Does Not Light (Astro, Safari & "S" Series)

Replace inoperative instrument cluster.

Voltmeter Is Inaccurate (Astro & Safari)

1. Check for short, open, or high resistance between alternator Brown wire and cluster. To do so, measure voltage between battery terminals. Now measure voltage between Brown wire and a know good ground.
2. If readings are different, repair Brown wire. If readings are the same, check Black ground wire for high resistance to ground. If Black wire is okay, replace inoperative instrument cluster.

Voltmeter Is Inaccurate ("S" Series)

1. Check for short, open, or high resistance between alternator Brown wire and cluster. Measure voltage between battery terminals. Now measure voltage between Pink/Black wire (terminal "A15") and a known good ground.
2. If readings are different, repair Pink/Black wire. If readings are the same, check Black ground wire at terminals "A9" and "B7" for high resistance to ground. If Black wire is okay, replace inoperative instrument cluster.

If warning light does not come on during bulb check, check for burned out light bulb. Replace bulb if necessary. If bulb is okay, check for an open in circuit. To do so, remove lead from differential pressure switch and ground lead. If warning light does not come on, find open in circuit. If light comes on, replace switch.

Removal & Installation (Astro, "C", "K" & "S" Series & Safari)

Raise and support vehicle. Unplug vehicle speed sensor harness. Remove bolt and vehicle speed sensor. Remove "O" ring. To install, reverse removal procedure.

Removal & Installation (Astro & Safari)

Disconnect negative battery cable. Disconnect harness from switch. Remove screws and trip switch. To install, reverse removal procedure.

Disconnect negative battery cable. Unplug instrument panel harness from connector. On Astro and Safari, remove digital ratio adapter controller and bracket from behind radio. Separate bracket from DRAC. On "S" series, remove DRAC from bracket below glove box. To install, reverse removal procedure.

Removal & Installation "C" & "K" Series

Remove instrument cluster. See INSTRUMENT CLUSTER. Remove DRA. To install, reverse removal procedure.

Scheme 6

1. Disconnect negative battery cable. Remove instrument panel trim plate screws. (Scheme 3) Remove steering column lower trim plate. Remove instrument cluster trim plate.
2. Remove instrument cluster screws and pull out cluster. Disconnect instrument cluster harness and speedometer cable. Remove instrument cluster. To install, reverse removal procedure.

Removal & Installation ("C" & "K" Series)

Disconnect negative battery cable. Remove radio and heater control units. Remove 4 retainer screws. Remove trim plate (A/T only). Remove instrument cluster. Disconnect 34-pin connector being careful not to touch circuit board pins. To install, reverse removal procedures.

Removal & Installation ("R" & "V" Series)

1. Disconnect negative battery cable. Remove headlight switch knob and radio control knobs. Remove steering column cover. Remove 8 screws attaching bezel and remove bezel.
2. Disconnect speedometer cable by depressing spring clip on rear of speedometer head and pulling cable free. (Scheme 6) Remove instrument cluster retaining screws and pull out cluster. Disconnect instrument cluster harness and remove cluster. To install, reverse removal procedure.

Removal & Installation ("G" Series)

1. Disconnect negative battery cable. Disconnect speedometer cable by depressing spring clip on rear of speedometer head and pulling cable free. Remove clock reset knob. Remove instrument cluster bezel retaining screws and bezel.
2. Remove lower instrument cluster retaining screws. Pull top of cluster away from dash panel and lift cluster out. Disconnect instrument cluster harness and remove cluster. To install, reverse removal procedure.

Removal & Installation ("P" Series)

1. Disconnect negative battery cable. Disconnect speedometer cable by depressing spring clip on rear of speedometer head and pulling cable free. Remove clock adjuster stem.
2. Remove instrument cluster bezel retaining screws and bezel. Disconnect instrument cluster harness and remove cluster. To install, reverse removal procedure.

Removal & Installation ("S" Series)

1. Disconnect negative battery cable. Remove light switch trim plate. Disconnect light switch harness. Remove A/C-heater control assembly. Disconnect A/C-heater control assembly harness.
2. Remove filler panel screws and panel. (Scheme 7) Remove instrument cluster housing nuts and cluster. Pull out instrument cluster and disconnect speedometer cable. Disconnect instrument cluster harness. To install, reverse removal procedure.

Scheme 7

Removal & Installation (Astro, Safari, "C", "G" & "K" Series)

Remove instrument cluster. See, in this article, appropriate INSTRUMENT CLUSTER removal procedure. Remove cluster case retainer screws and retainer (if equipped). Remove gauge mounting screws. Carefully remove gauge(s). (Scheme 4) To install, reverse removal procedure.

1. Disconnect negative battery cable. Remove headlight switch and radio control knobs. Remove clock adjuster stem. Remove instrument cluster bezel. Remove steering column cover.
2. Remove instrument cluster lens and transmission shift indicator. If necessary, remove instrument cluster case front cover or retainer. Remove screws from gauge being serviced. Remove gauge(s). To install, reverse removal procedure.

Remove instrument cluster. Remove instrument cluster lens and lens retainer. Remove printed circuit board. Remove nuts from gauge being serviced. Remove gauge(s). (Scheme 5) To install, reverse removal procedure.

Remove instrument cluster. Remove light socket assemblies. Remove printed circuit board. See PRINTED CIRCUIT in this article. Remove instrument cluster case retaining screws. Remove instrument cluster case from bezel. Remove screws from gauge being serviced. Remove gauge(s). To install, reverse removal procedure.

Remove instrument cluster. Remove speedometer retaining screws and speedometer. (Scheme 3) To install, reverse removal procedure.

Disconnect negative battery cable. Remove instrument cluster. See INSTRUMENT CLUSTER in this article. Remove retainer screws and retainer. Remove speedometer mounting screws. Carefully remove speedometer without touching circuitry. To install, reverse removal procedure.

Remove instrument cluster. Remove speedometer retaining screws. Remove 2 Torx head screws and rubber grommets securing speedometer assembly to cluster cover. Disconnect speedometer cable and remove speedometer. To install, reverse removal procedure.

1. Remove instrument cluster. Remove light socket assemblies. Remove printed circuit retaining nuts. Remove printed circuit. Remove instrument cluster case retaining screws.
2. Remove instrument cluster case from bezel. Remove speedometer retaining screws. Disconnect speedometer cable and remove speedometer. To install, reverse removal procedure.

1. Disconnect negative battery cable. Remove headlight switch assembly. Remove radio control knobs. Remove clock adjuster stem. Remove instrument cluster bezel.
2. Remove steering column. Remove instrument cluster lens. Remove transmission shift indicator. Remove instrument gauge retainer. Depress spring clip on speedometer cable and release cable from speedometer. To install, reverse removal procedure.

Removal & Installation "G", "P", "R" & "V" Series

Remove instrument cluster. Remove instrument cluster light socket assemblies. Remove printed circuit board retaining screws. On "G" and "P" series, remove fuel gauge, temperature gauge, and ammeter terminal nuts. On all models, remove printed circuit board. To install, reverse removal procedure. Ensure gauge and ammeter terminal nuts are securely tightened.

Instrument Panel Calibration Specifications. Scheme 8

See also:
• INSTRUMENT PANEL CALIBRATION SPECIFICATIONS
• ELECTRONIC INSTRUMENT CLUSTER TEST
• BUFFER OUTPUT DIAGNOSIS
• BUFFER POWER DIAGNOSIS