SYMPTOM RELATED DIAGNOSTICS

ON/OFF FAN CONTROL VERBAL COMPLAINT (continued)

Test 39

Checking for correct plumbing of the solenoid

1.Tighten the air supply line.

2.Remove the vent cap or vent line from the solenoid.

If air flows out of the vent, the solenoid is plumbed incorrectly. Reverse the vent and air supply lines on the solenoid and retest the fan drive.

If air does not flow out of the vent, the solenoid is defective. Repair or replace the solenoid and retest the fan drive.

Test 64

Checking for 12 volts at the V-MAC II module

5.Connect the serial link jumper into the serial communication port.

6.Measure the voltage from J1B connector pin Y2 (the Auxiliary No. 1 output line) to a good ground.

If 12 volts are present, proceed to Test 128.

If 12 volts are not present, proceed to Test 129.

Checking override switch operation

1.Turn the ignition key to the OFF position.

2.Reconnect the harness to the freon fan pressure switch.

3.Disconnect the J1B connector from the V-MAC II module.

4.If there is an override switch on the dash, turn it to the OFF or normal operation position.

If a manual override switch used, set the switch to the ON or override position.

If a manual override switch is not used, proceed to Test 256.

1.Measure the voltage from J1B connector pin Y2 (the Auxiliary No. 1 output line) to a good ground.

If 12 volts are present, proceed to Test 257.

If 12 volts are not present, turn the override switch to the OFF position, proceed to Test 256.

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