1990 760T StationWagon

Symptoms: Blower was working fine. Then it started working intermittently, sometimes only working on "5" (on the control ****; which is full on blast). Sometimes the blower wouldn't turn on at all.

We suspect that blower motor is fine but that blower resistor is failing. We have removed the resistor pack (remove 2 screws and it comes out of plenum) ... it has a black cover with some holes in it on the circuit board side and it has an aluminum heat sinc on the back of it (the sinc sits inside the plenum).

Question #1: things are working OK now. But "intermittent" means that when we need it, it will probably fail. How do I diagnose whether in fact the resistor pack is faulty?

Question #2: after we took the resistor pack out of the plenum, we could see a ton of pine needles and other sundry vegetable matter caked up on half of the heater core. We obviously want to clean that out. But, does the black plastic cover facing to rear of vehicle that covers the heater core just come off? We removed the screws on the cover but it seems that it is sealed in with some sort of caulk or adhesive.

Thank you for your help.

 

We swapped resistor packs with another working vehicle (same make/model/yr) and the problem has followed the part.

So, is there a place for cheap used parts? I'll look at PicknPull.

How about a parts interchange? Like, can a 960 and 760 interchange on this? What about a 740 and 760?