Instrument Panel - Except "s" Series GMC Cab & Chassis R2500

DESCRIPTION

All instruments and gauges are installed in instrument cluster. Indicator lights and illuminating bulbs may be replaced without removing instrument cluster from vehicle on all models.

FUEL GAUGE

FUEL GAUGE SENDING UNIT RESISTANCE SPECIFICATIONS

"C", "G", "K" & "P" Series

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.

Removal & Installation ("C" & "K" 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 1) Remove instrument cluster retaining screws and pull out cluster. Disconnect instrument cluster harness and remove cluster. 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.

1. Disconnect negative battery cable. Remove headlight switch knob. Remove radio control knobs. Remove clock adjuster stem. Remove instrument cluster bezel.
2. 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 "C", "G", "K" & "P" Series

1. 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.
2. On all models, remove printed circuit board. To install, reverse removal procedure. Ensure gauge and ammeter terminal nuts are securely tightened.

("C" & "K" Series)

1. Disconnect negative battery cable. Reach behind instrument panel and remove headlight switch knob and shaft by depressing retaining button. Remove trim panel and bezel.
2. Disconnect headlight switch wiring harness. Remove headlight switch. To install, reverse removal procedure.

OIL PRESSURE GAUGE SENDING UNIT RESISTANCE SPECIFICATIONS

OIL PRESSURE GAUGE SENDING UNIT RESIS SPECS

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 step 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 midscale with 90 ohms from tester, tighten nuts and install gauge. If gauge is still inaccurate and nuts are tight, replace gauge.

Scheme 1

TEMPERATURE GAUGE

TEMPERATURE GAUGE SENDING UNIT RESIS SPECS

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.

SPEEDOMETER

1. If speedometer is noisy, 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.