Magnetic Clutch and Condenser Fan Do Not Operate

Normal Operation
The ECM controls the condenser fan and magnetic clutch depending on the A/C signal. When the A/C and fan switches are on, the A/C signal circuit is grounded. The ECM then closes the A/C and condenser fan relay ground circuits.

If the refrigerant pressure becomes abnormal, the refrigerant pressure switch will open the A/C signal circuit. If the evaporator temperature becomes too low, the thermoswitch will open the A/C signal circuit. The ECM then cuts off the above two relays to prevent damage to the refrigerant system.


Step 1
1. Disconnect the refrigerant pressure switch connector.
2. Turn the ignition switch to ON.








3. Measure the voltage at terminal B of the refrigerant pressure switch connector.


Step 2

1. Turn the ignition switch to LOCK.
2. Verify that the refrigerant pressure is in normal range.








3. Check for continuity between terminals of the refrigerant pressure switch.


Step 3
1. Turn the ignition switch to ON.








2. Measure the voltage at the terminal wires of the thermoswitch connector.


Step 4
1. Turn the fan switch on.








2. Measure the voltage at terminal F of the heater control unit connector while operating the A/C switch