Tachometer Circuit Test
- Remove instrument cluster. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. Check for battery voltage at cavity No. 8 (Pink wire) of instrument cluster Red connector. See Figure
. Turn ignition on. Check for battery voltage at cavity No. 9 (Dark Blue/White wire) of instrument cluster Red connector. If battery voltage is not present at both locations, repair wiring as necessary.
- If battery voltage is present, check cavity No. 14 (Black/Orange wire) of instrument cluster Red connector for continuity to ground. If continuity is not present, repair wiring as necessary. If continuity is present, check for tachometer signal by connecting an AC digital voltmeter to ground and to cavity No. 6 (Gray/Light Blue wire) of cluster Black connector. See Figure
.
NOTE:
PCM is located in engine compartment, near battery, and contains a 60-pin connector. See Fig 1
.
- A pulsating voltage reading of a minimum of one volt should be present with engine running. If voltage is correct, proceed to step 5). If voltage is less than one volt, check for wire continuity between cavity No. 6 (Gray/Light Blue) of cluster Black connector and pin No. 43 (Gray/Light Blue wire) of PCM 60-pin connector. See Figure
and Fig 1
.
- If continuity is not present, repair wiring as necessary. Ensure PCM and its connector do not have damaged pins or poor connections. If continuity exists between cavity No. 6 and pin No. 43, replace PCM and retest.
- If all tests performed are good and tachometer is still inoperative, replace tachometer drive module. Tachometer drive module is attached to printed circuit board on rear of instrument cluster. If tachometer is still inoperable, replace tachometer assembly.
Courtesy of CHRYSLER CORP.