Instrument Panels - Analog: Testing: Tachometer
CAUTION:
When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See the COMPUTER RELEARN PROCEDURES
article in the GENERAL INFORMATION section.
- Verify fuse is okay. Inspect for loose connections in engine compartment or at instrument cluster. Secure where necessary. Remove instrument cluster. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION.
- Measure resistance between pin No. 3 (Black wire) of Black instrument cluster harness connector and ground. Repair Black wire if resistance is greater than one ohm. See Fig 1 .
- For 6-cylinder engines, go to step 4). For 8-cylinder engines, measure resistance between pin No. 10 (Black /Yellow wire) of Black instrument cluster harness connector and ground. Repair Black /Yellow wire if resistance is greater than one ohm. If resistance is as specified, go to step 5).
- For 6-cylinder engines, test for continuity between pin No. 10 (Black /Yellow wire) of Black instrument cluster harness connector and ground. Continuity should not exist. Repair short to ground in Black /Yellow wire if continuity exists.
- Measure resistance between pin No. 9 (White/Pink wire) of Black harness connector and negative terminal of ignition coil. Repair White/Pink wire if resistance is greater than one ohm.
- Connect battery. Turn ignition on. Test for battery voltage at pin No. 13 (Red /Yellow wire) of Black connector. If battery voltage does not exist, repair Red /Yellow wire from fuse panel. Turn ignition off. Disconnect battery.
- If indications are as specified, inspect for loose or missing cluster connection clips. Reseat or replace missing clips. Inspect for damaged printed circuit. Replace printed circuit as necessary. If connection clips and printed circuit are okay, replace tachometer.