2005 Chevy Silverado Heater AC Eng Temp Multiple related pr

2005 CHEVROLET SILVERADO
42,000 MILES • V8 • 2WD • AUTOMATIC
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JIMNKRISTY
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  • 1 POST
I have a 2005 Chevy Silverado that is having a problem with the blower motor control switch. The 5 speed went out first while 1 - 4 still worked. Then 4 went out. I still have 1-3. This all happened during the summer so I only noticed it with the AC. I recently turned on the heater and found that the blower only worked in 1 - 3 and the heater does not blow hot air consistently. It sometimes blows warm, then cold and the truck temperature also fluctuates from about 200 to 255. If I turn off the heat, back to cool, the vehicle temp goes back to 200 and stays there. I read that the blower resistor is a common problem and I have considered that, but the engine temp flux also has me concerned. Can the resistor cause that too? Its going to be getting cold soon, so any help would be greatly appreciated.
Jim
Oct 8, 2009 at 7:24 PM
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TEX3523
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As far as the fan speed. I had fans speed 1 go out in my 2000 silverado. chevy redesigned the resistor, for a more robust one. I replaced it and works fine. It is located next to the heater fan on the passenger side floorboard.
As far as your temp. flucuations, does this happen when you have the defroster only or also when in just heat mode. If defrost only, possible problem with cooling system when A/C pump comes on. The A/C pump comes on on Defrost to dry the air. Do you get the problem when A/C is on? Also sounds like your clutch fan is not working properly, because it should come on about 220 or so to force more air through the radiator. You will definitely hear it when engages. Another thing to cause flucuations is your thermostat. Pehaps its opening and shutting erratically, but should happen all the time, not just when heater is on.
Oct 12, 2009 at 3:23 PM