Circuit/System Testing
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IMPORTANT:
You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
- Ignition OFF, disconnect the series/parallel fan relay.
- Ignition ON, activate the cooling fan relay 1 with a scan tool. The fan should be OFF.
- If the fan is activated, test the left fan ground circuit for a short to ground.
- Ignition OFF, disconnect the remaining fan relays.
- Connect a 30A fused jumper between the normally-open switch contact terminals at the fan control relay connector in order to complete the left fan ground circuit. Leave this jumper in place for the remainder of this procedure.
- One at a time, connect a 30A fused jumper between the positive terminal at the battery and the fan voltage supply circuit terminal at each relay connection and verify the appropriate fan activation.
- If the appropriate fan does not activate, test the fan voltage supply circuit for a short to ground or open/high resistance. If the circuit tests normal, test the fan ground circuit for open/high resistance. If the circuits test normal, replace the fan.
- Ignition ON, connect a 30A fused jumper between the relay switch voltage supply circuit terminal and the fan voltage supply circuit terminal at the low speed and then the high speed relay connections and verify the appropriate fan activation.
- If the appropriate fan does not activate, test the relay switch voltage supply circuit for a short to ground or high resistance.
- If the circuits and fans test normal, replace the relay.