Fuel Gauge Circuit & Fuel Gauge Sending Unit Test
NOTE:
When a problem occurs with any gauge, before disassembling cluster to test gauge(s), check for loose connections or faulty wiring.
- Remove cluster bezel from instrument panel. Refer to CLUSTER BEZEL R & I under REMOVAL & INSTALLATION. Remove fuel gauge retaining screws (if equipped). Remove fuel gauge by pulling straight out from cluster. DO NOT turn or twist gauge when pulling, or severe damage to cluster pins will result. See Fig 1 -Fig 4 .
- Turn ignition on. Using voltmeter, check for battery voltage at fuel gauge (B+) pin. See Fig 1 -Fig 4 . Using ohmmeter, check for ground continuity at fuel gauge ground pin. If voltage and ground are not present at pins, go to step 3). If voltage and ground are present at proper pins, go to step 5).
- If voltage and ground are not present at pins, remove instrument cluster. See INSTRUMENT CLUSTER R & I under REMOVAL & INSTALLATION. Check for battery voltage and ground at appropriate cluster harness connectors. See Figure , Figure -Figure . On Daytona and LeBaron Convertible/Coupe, see INSTRUMENT CLUSTER CONNECTOR CAVITY ID . See WIRING DIAGRAMS .
- If voltage and ground are NOT present at cluster harness connectors, repair wiring as necessary. If voltage and ground are present at cluster harness connectors, check cluster for bent or broken terminal pins. If terminal pins are okay, replace cluster printed circuit board and retest.
- To check sending unit resistance, remove fuel sending unit from tank. Ensure fuel sending unit is not damaged. Reconnect tank sending unit to harness connector. Ensure sending unit and connector are properly grounded to vehicle.
- Position sending unit float to FULL position. Using ohmmeter, check resistance reading at fuel sender input pin of cluster. See Fig 1 -Fig 4 . If reading is infinity, repair open in wiring circuit from cluster to sending unit. Correct reading should be within 4 ohms of specification. See FUEL GAUGE CALIBRATION . Position sending unit to other positions and check resistances to match table.
- If sending unit resistances do not match table, replace sending unit. After ensuring sending unit resistances are satisfactory, with ignition off, position fuel gauge onto cluster pins and install by pushing gauge straight inward onto pins.
- Turn ignition on. Position sending unit to previously checked resistance positions and note position of fuel gauge after 15 seconds. If fuel gauge pointer position is not relative to sending unit position, replace fuel gauge.
FUEL GAUGE CALIBRATION
| Resistance | Position |
|---|---|
| 90 Ohms | E |
| 59 Ohms | 1/4 |
| 42 Ohms | 1/2 |
| 28 Ohms | 3/4 |
| 12 Ohms | F |
INSTRUMENT CLUSTER CONNECTOR CAVITY ID (AG & AJ BODIES)
| Cavity No. | Function | |
|---|---|---|
| Black Connector | ||
| 1 | Left Turn Signal | |
| 2 | Right Turn Signal | |
| 3 | Not Used | |
| 4 | Not Used | |
| 5 | Distance Sensor (Speed Sensor) | |
| 6 | Tachometer Signal | |
| 7 | Fuel Tank Sending Unit | |
| 8 | Panel Illumination | |
| 9 | Low Fuel Warning Light | |
| 10 | Not Used | |
| 11 | Coolant Temperature Sending Unit | |
| 12 | Low Oil Pressure Warning Light | |
| 12 | Or CHECK GAUGES Light | |
| 13 | Low Oil Warning Light | |
| 14 | Not Used | |
| Red Connector | ||
| 1 | Seat Belt Indicator | |
| 2 | Not Used | |
| 3 | ANTI-LOCK Warning Light | |
| 4 | Not Used | |
| 5 | BRAKE Warning Light | |
| 6 | AIR BAG Warning Light | |
| 7 | Not Used | |
| 8 | Battery Voltage | |
| 9 | Ignition Power | |
| 10 | High Beam Indicator | |
| 11 | CHECK ENGINE Warning Light | |
| 12 | Not Used | |
| 13 | Foglight Indicator | |
| 14 | Ground | |