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Dan, ASE Certified Technician
Category: Buick
Satisfied Customers: 2270
Experience:  20 Year Factory Trained Current GM Technician
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1995 Buick Park Avenue: with atc have blower relays..resistor ($120

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Does 1995 Buick Park Avenue with ATC have blower relays? Where are they located exactly? How can I make sure the resistor ($120-180) is the problem?

My HVAC blower does not work, but fan runs when jumped directly to battery. This car seems to have a pricey solid state variable voltage supply in heater shroud versus a standard blower resistor. I cannot find anywhere the location of blower relay(s) on-line (#1, 2, from left etc.), and I am starting to wonder if this car with ATC has blower relays. (Two slots on relay rail are empty.) Also wondering how to test if "resistor" module is relay bad. There are two connectors, one with 12 V (is live) and another with I guess with ground, wire from control panel and wire to blower. Am I on right track?
this car has no blower relays. The blower control module gets a signal from the HVAC Programer and adjusts the bloower speed according to the voltage from the programer.
You are on the right track by the way I read what you have done. you need to check the voltage from the programer( the gray wire with the black stripe) while the blower is set to high speed.
Here is the dia chart for this:
Dan and 4 other Buick Specialists are ready to help you
Customer: replied 7 years ago.
Thanks! I think this is exactly the kind of info I need, other advice has been for non ATC units, check relays etc.! As first time person I did not know what to expect.

This voltage from programmer (gray wire with black stripe) is on connector to control module, maybe C2 terminal B? I got a reading on one of those wires, maybe 4 or 6 Volts. If that was it and 4 Volts, is the programmer (dash unit?) really bad?
With the blower on hi and in defrost mode it should read 6-8 volts. with the blower set lower speed it will produce less voltage. Even at 4-6 volts, it should have a lower blower speed. WHen the progremer is bad, it normally will not produce any voltage.

Customer: replied 7 years ago.
Got it! So this gray wire with black stripe is on connector to control module, maybe C2 terminal B, the connector with three versus two pins?

When I try again tomorrow, the gray/black wire should be easy to find.

Thanks again!

C2 (connector 2) A is the purple wire that goes to the blower motor
B is the Gray wire with black stripe that gets a signal from the processor
C is Ground the black wire

C1 Terminal B has a red wire for the Power supply.

Dan and 4 other Buick Specialists are ready to help you
Customer: replied 7 years ago.

With your help I fixed the blower. The voltage to the control module was there, but actually higher (9.5 V) than I expected to get. I went ahead and changed the controller ($120) and it has been running since. Was quite a job to remove relay rail and get at controller with the screws in akward places, but I did it. I am surprised that new controller with one transistor can power the fan, but so far so good. Thanks for your help. Swampy
Yea, the Caddys and the corvettes have the same system, I replaced a few of them in my life for this problem. Thanks for the update.

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