Greetings Jeric,

If memory serves me right than your aux fan is controlled by the freon temp sensor located on the receiver dryer. It should be the one threaded into the top side and made out of brass. If you connect the two wires going to it and the a/c is running then the fan should start up. It comes on at 52 degrees C If your a/c has been on for a few minutes at idle the fan should be running, if not bypass this temp switch and see what happens. Chances are good that this switch is your problem child.

Charles