Timer Input Test
- Locate condenser fan timer unit under center of dashboard, but DO NOT disconnect harness connector. Turn ignition on. Using a DVOM, check for voltage between terminal No. 4 (Black wire) and chassis ground. See Fig 1 .
- If voltage reading is greater than zero but less than one volt, go to next step. If voltage reading is zero, repair open circuit between fan timer unit and chassis ground. If voltage reading is greater than one volt, repair short to power.
- Check for voltage between terminal No. 6 (White wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, check fuse No. 20. If fuse is okay, repair open circuit in White wire between fuse block and fan timer unit.
- Check for voltage between terminal No. 7 (Black/Yellow wire) and ground. Battery voltage should only exist with ignition on. If voltage reading is as specified, go to next step. If voltage reading is not as specified, check fuse No. 24. If fuse is okay, repair open circuit in Black/Yellow wire between fuse block and fan timer unit.
- Check for voltage between terminal No. 2 (Yellow/Black wire) and ground. Battery voltage should only exist with ignition on. If voltage reading is as specified, go to next step. If voltage reading is not as specified, check fuse No. 21. If fuse is okay, repair open circuit in Yellow/Black wire between fuse block and fan timer unit.
- Check for voltage between terminal No. 1 (Yellow/White wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, replace fan timer unit.CAUTION: Before replacing fan timer unit, turn ignition off. Using an ohmmeter set at 20,000-ohm scale, check for continuity between terminal No. 1 (Yellow/White wire) of timer connector and chassis ground. If continuity exists, new timer will be damaged when connected. Repair short circuit in Yellow/White wire before connecting fan timer unit.
- Using a jumper wire, connect terminal No. 8 (Blue/Red wire) to ground. If condenser fan turns on, go to next step. If condenser fan does not operate, check for open circuit in Blue/Red wire between fan timer unit and condenser fan relay.
- If wire is okay, check for open circuit in Yellow/White wire between fan timer unit and 2-pin connector located near radiator and Black/Yellow wire located between 2-pin connector and condenser fan relay. If wiring is okay, test condenser fan relay. See TROUBLE SHOOTING CHARTS under TROUBLE SHOOTING .
- Check for voltage between terminal No. 5 (White/Green wire) and ground. With engine oil temperature below 226°F (108°C), voltage reading should be approximately 11 volts. If voltage reading is not as specified, check for short to ground in White/Green wire. If wire is okay, check oil temperature switch. If oil temperature switch is okay, install a known good fan timer unit, and retest.