EFE Relay: Testing and Inspection

1. Remove PTC heater relay with coupler connected.
2. With ignition switch Off, disconnect ECM coupler.

Fig. 144 Checking Voltage At PTC Relay:

3. Turn ignition switch On, check voltage at A, C and D terminals using voltmeter, Fig. 144. Battery voltage should be present at all terminals. If battery voltage is not present, light green/red wire or white/blue wire may be open or white/green wire is shorted to ground.

Fig. 145 Checking PTC Relay Operation:

4. Using same gauge wire as used for relay circuit, connect D terminal and ground, Fig. 145, then turn ignition switch On. Relay should operate and battery voltage should be applied to terminal B.
5. If test in step 4 is not satisfactory, replace PTC heater relay.