Cadillac Repair: 1987 Cadillac Fleetwood, cadillac fleetwood, engine vacuum

Question
The heater will only blow onto the floor and no defrost,can you help me please?

Answer
Hi Kyle,

      To answer your question I will need to know if your Fleetwood is front or rear drive. At this point the best suggestion I can give is to start the engine and set it to defrost or vent and then remove a vacuum hose from a mode door motor. If it has vacuum at the hose see if the door moves when plugged in. If so when it is ok. If no movement then that door motor might need to be replaced before the air will go to that outlet. The exception is a motor that has 2 hoses going to it. There are 4-5 motors so make sure to check them all.

    Inside the programmer...where the 5 vacuum hoses come out of a black plastic box behind the glovebox area...there is a vacuum plug that sometimes leaks or cracks off. that can cause lack of door movement.

     Also at the programmer remove the vacuum harness plug and with the engine running see if engine vacuum is there...the black tube is the supply I think...and how much is availabe using a gauge. It could be that a vacuum line has cracked or fallen off somewhere and there isn't any vacuum available to move the doors. If you have good hearing you should be able to hear a vacuum leak eithor inside the car or under the hood with the engine running.

      Start with that and if you need more help let me know what happens and what module you have...FWD or RWD. Bill