Dakota 4WD V6-239 3.9L Magnum (1996)
Tachometer: Testing and Inspection
1. With engine running, check for tachometer signal at PCM connector C (gray).If signal is not present, test or replace PCM; if signal is present,
continue with procedure.
2. Disconnect battery ground cable and PCM connector, then remove instrument cluster and bezel assembly and disconnect connector at lefthand
side of cluster.
3. Probe the tach signal circuit cavity on left connector for continuity to ground. If continuity exists, repair short as necessary; if not, continue with
procedure.
4. Check for continuity between the tach signal cavity of the connector and PCM connector cavity. If continuity exists, continue with procedure; if
not, repair open as necessary.
5. Replace tachometer drive module with a known good module, then test vehicle for proper tachometer operation. If tachometer now functions
properly, install new module permanently; if not, replace tachometer.
6. If tachometer needle does not return to 0 when ignition switch is placed in Off position, check for battery voltage at the fused B(+) circuit cavity of
the left instrument cluster connector and repair open circuit as necessary.