Fuel Gauge & Wiring Harness Operational Test
- Unplug fuel tank sending unit connector. Turn ignition on. If fuel gauge indicates EMPTY, go to next step. If fuel gauge does not indicate EMPTY, repair short in wiring harness. See «WIRING DIAGRAMS»(ref-33976-S31221264572001010900000).
- Connect a 12-volt, 3.4-watt test light between appropriate terminals of sending unit wiring harness connector. (Scheme 1) See «FUEL GAUGE & HARNESS TEST»(ref-33976-S23695396542001010900000) table.
- With ignition on, test light should flash and gauge needle should move toward FULL. If test light does not flash and gauge needle does not move, check wiring harness for open. Repair or replace as necessary. If wiring harness checks good, replace fuel gauge.
| Model | Sending Unit Connector Terminals No. |
|---|---|
| LX450 | 4 & 5 |
FUEL GAUGE & HARNESS TEST
Scheme 1
Low Fuel Warning Light Sensor Operational Test
- Remove fuel sending unit from gas tank. Using a battery, connect voltage to warning light sensor terminals of sending unit connector. See «LOW FUEL WARNING LIGHT SENSOR TERMINALS»(ref-33976-S38983078402001010900000) table.
- Connect a 12-volt, 3.4-watt test light between positive battery terminal and one warning light sensor terminal of sending unit connector. Connect other warning light sensor terminal to negative battery terminal.
- With sending unit float/sensor dry, test light should come on within about 40 seconds. With sending unit float/sensor submerged in gasoline or water, test light should not come on. If test light does not function as described, reverse wire connections at battery terminals and retest. If test light still does not function as described, replace sensor or complete sending unit.
| Model | Sending Unit Connector Terminals No. |
|---|---|
| LX450 | 1 & 3 |
LOW FUEL WARNING LIGHT SENSOR TERMINALS
Wiring Harness Operational Test
- Unplug connector at coolant temperature sender. Turn ignition on. Temperature gauge should indicate COOL. Turn ignition off. Connect a 12-volt, 3.4-watt test light between coolant temperature sender harness connector terminal and ground.
- Turn ignition on. Test light should glow and temperature gauge should slowly move to HOT. If gauge functions as described, replace sending unit. If gauge does not function as described, perform TEMPERATURE GAUGE RESISTANCE TEST below.
Oil Pressure Gauge & Harness Operational Test
- Unplug oil sending unit connector on engine. Turn ignition on. Oil gauge should indicate LOW. Turn ignition off. Connect a 12-volt, 3.4-watt test light between oil sending unit harness connector terminal and ground.
- Turn ignition on. Test light should glow and oil pressure gauge should slowly move to HIGH. If gauge functions as described, perform SENDING UNIT OPERATIONAL TEST below. If gauge does not function as described, perform OIL PRESSURE GAUGE RESISTANCE TEST below.
Sending Unit Operational Test
Unplug oil sending unit connector on engine. Using 12-volt source, connect LED tester between positive battery terminal and sending unit. With engine off, LED should not light. With engine running, LED should flash. LED flashes will vary with engine speed and oil pressure. Replace sending unit if LED does not function as described.