Test E - Tachometer Inaccurate
- Turn ignition off. Remove instrument cluster. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. Disconnect instrument cluster electrical connector C3. See Figure . Turn ignition on. Measure voltage between ground and instrument cluster harness connector C3, terminal No. 8 (Black/Yellow wire). Voltage should be greater than 10 volts. If voltage is greater than 10 volts, go to next step. If voltage is less than 10 volts, repair Black/Yellow wire between instrument cluster connector and fuse. See WIRING DIAGRAMS .
- Turn ignition off. Measure resistance between ground and instrument cluster harness connector C3, terminal No. 7 (Black/Green wire). See Figure . Resistance should be less than 5 ohms. If resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, repair Black Green wire between instrument cluster connector and ground. See WIRING DIAGRAMS .
- Visually inspect instrument cluster printed circuit for damage, cracks or hot spots. If instrument cluster printed circuit is okay, go to next step. If instrument cluster printed circuit is damaged, replace printed circuit and gauge contact clips. See PRINTED CIRCUIT under REMOVAL & INSTALLATION.
- Install EEC-V 104-pin Breakout Box (014-00950) following manufacturer's instructions. Measure resistance between breakout box terminal No. 48 and instrument cluster harness connector C3, terminal No. 6 (Light Green/Red wire). See Figure . Resistance should be less than 5 ohms. Measure resistance between ground and instrument cluster harness connector C3, terminal No. 6 (Light Green/Red wire). Resistance should be greater than 10 k/ohms. If both resistances are as specified, replace tachometer. See TACHOMETER under REMOVAL & INSTALLATION . If resistances are not as specified, repair Light Green/Red wire. See WIRING DIAGRAMS .