Cold Advance Solenoid: Testing and Inspection

Fig. 36 Cold Advance Control (CAC) Circuit schematic. 1988 V8-379 diesel:

1988 V8-379

1. With engine coolant temperature below 80°F, place ignition switch in the On position.
2. Probe cold advance solenoid electrical connector with test light connected to ground, Fig. 36. If test light is illuminated, the electrical system is functioning properly. Check to cold advance solenoid for proper operation, by removing pump cover as described under "CAC Solenoid, Replace", then apply 12 volts D.C. to solenoid. If test light is not illuminated, proceed to step 3.
3. With test light connected to ground, probe cold advance relay terminal A. If test light is illuminated, check for open circuit between relay and cold advance solenoid. If test light is not illuminated, proceed to step 4.
4. With test light connected to a 12 volt D.C. power source, probe cold advance relay terminal D. If test light is not illuminated, check for open circuit from relay to Electronic Control Module (ECM). If circuit is satisfactory, refer to "Diesel Electronic Control (DEC) System" section for ECM test. If test light is illuminated, proceed to step 5.
5. With test light connected to ground, probe relay terminal F. If test light is not illuminated, check ECM 10 amp fuse. If fuse is satisfactory, check for open in relay terminal F wiring circuit. If test light is illuminated, proceed to step 6.
6. With test light connected to ground, probe relay terminal E. If test light is not illuminated, check Gages 20 amp fuse. If fuse is satisfactory, check for open in terminal E wiring circuit. If test lamp is illuminated, replace cold advance relay.