Heating AC and Engine Cooling
Heater Cores and Blower Fans
Oldsmobile Alero

The heater fan only works on speeds 4 and 5 on a 1999 alero where is the heat resistor and is it hard to change itHow do you test the old one to see if it is faulty?


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2005-07-06 07:27:27
2005-07-06 07:27:27

Your lower resistor for the HVAC blowing unit is bad. You can buy this part at a carquest if you have one nearby for less than $20. I did some research on this since my 1999 alero had the same issue. I replaced it, and it did work for a little while (less than two weeks). However, it failed again, so i am stuck with my heater/ ac blower only working on High. I cannot locate the instructions I used to replace the resistor, but i can give you an idea, and you should be able to figure it out from there. Here are my simple steps: #1) First, you should buy the lower resistor for your HVAC unit from carquest or another parts store. is too pricey, but if you go to them or your local gm dealer, you can get the part as well... If you just explain the problem they should know what you need, but it is called the lower resistor for the HVAC blower unit. #2) after you have the part in hand, you will see that it has a wire connector (female end) and a credit card sized chip attached to it. #3) The blower motor is on the passengers side of the car, on the floorboard at the very front of the car attached to the firewall, you will have to lay on your stomach and look up to see the wire harness that attaches to this lower resistor. #4) the size of the nut is 7/32. A socket is probably they easist method on the FRONT nut, on the rear nut, you will probably have to use a 7/32 wrench, i bought mine at craftsman. Basically, locating the resisor is the easy part, i had extreme difficulty trying to get the resistor out, but i eventually did, and replaced it. Like i said before, mine crapped out again in less than a week, so i have not replaced it again, i figure that i can live with my blower working on only high, atleast it still works...


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You most likely have a problem with your blower RESISTOR PACK or rheostat. This is what controls the high, med and low speeds on your heater. Where it is and how to change it depends on your vehicle.

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