Test F: Tachometer Inoperative
- Turn ignition switch to LOCK position. Remove instrument cluster. See INSTRUMENT CLUSTER
under REMOVAL & INSTALLATION. On models equipped with 4.0L engines, measure resistance between ground and terminal No. 8 (Black/Yellow wire) at instrument cluster White 10-pin harness connector. See Figure
. On models equipped with 5.0L engines, measure resistance between ground and instrument cluster White 16-pin harness connector C286 terminal No. 16 (Black/White wire). See Figure
. On all models, if resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black/White or Black/Yellow wire between instrument cluster connector and ground. Recheck system operation.
- Turn ignition switch to LOCK position. Disconnect Powertrain Control Module (PCM) 104-pin harness connector C202. PCM is mounted on cowl in right rear of engine compartment. Install EEC-V 104-Pin Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between terminal No. 15 (Tan/Yellow wire) at instrument cluster White 16-pin connector and breakout box test pin No. 48. If resistance is less than 5 ohms, remove breakout box. Reconnect PCM and go to next step. If resistance is 5 ohms or more, repair open in Tan/Yellow wire between instrument cluster and PCM. Recheck system operation.
- Start engine and allow to idle. Measure voltage between ground and instrument cluster White 16-pin harness connector C286 terminal No. 15 (Tan/Yellow wire). If 5-8 volts exist, go to next step. If 5-8 volts does not exist, replace PCM. See POWERTRAIN CONTROL MODULE
under REMOVAL & INSTALLATION. Recheck system operation.
- Measure resistance of printed circuit between tachometer pins (in center of clips) and corresponding instrument cluster harness connector terminals. See TACHOMETER PRINTED CIRCUIT CHECK
table. If all resistance measurements are less than 5 ohms, replace tachometer. See GAUGES
under REMOVAL & INSTALLATION. Recheck system operation. If any resistance measurement is 5 ohms or more, replace instrument cluster printed circuit. See PRINTED CIRCUIT
under REMOVAL & INSTALLATION. Recheck system operation.
TACHOMETER PRINTED CIRCUIT CHECK
| Tachometer Pin |
Instrument Cluster Connector (Terminal No.) |
| "B" |
White 16-Pin Connector C286 (13) |
| Lower "G" |
Black 12-Pin Connector C287 (2) |
| Upper "G" |
White 10-Pin Connector C288 (8) |
| 4.0L |
|
| 5.0L |
White 16-Pin Connector C286 (16) |
| "S" |
White 16-Pin Connector C286 (15) |