Cadillac Repair: Blower motor, cadillac deville, fan thanks

Question
1979 cadillac deville. Blower motor fails to turn on , Changed thermostat on control panel. only thing i think it can be is the ACT programmer. Will this part cause this problem. Blower is good. This problem started out with the blower either staying on after you turned the car off, then not coming on at all, Compressor gets cold but no fan . Thanks For any suggestings   Mark

Answer
There is a BLOWER switch down deep in the head on the passengers side of the engine at the front of the head. I believe it has a GREEN wire going to it. GROUND out this single green wire and see if the blower runs. If it does, replace the sensor or just ground out the wire.

This temp switch may also be located on the drivers side of the engine back near the last 2 spark plugs on the side of the block and also is a green wire.

This switch was famous for going bad.