Pontiac Repair: 1995 pontiac transport heater repair, pontiac transport, defog

Question
I have a 1995 pontiac transport and the heater does not work. It will only blow out in defog and only in low. if i switch to high it shuts off. In the defog it will only blow on low and air is cold. thanks any help appreciated

Answer
Hey Rich:

I think you have 2 issues here. There is something either wrong with the blower switch or the resistor for the motor is bad It only works on low #1 or all low speeds and not hi? If just Hi then I would suspect the high blower relay. I think you have a door/actautor issue on this if the air only comes out of defogger. I belive on thos older ones the doors were still vacuum operated. so if the system lost vacuum the air would default out defrost. I would look for a vacuum leak under the hood the hoses are on the right side of the van from the engine to the body harness look there for a broken hose or on the engine. It's unlikely the heak is inside the van but it's possible. It could also be the control valve assembly in the van that distributes the vacuum to the different actuators. good luck :}