problems with heater fan control switch

I have a 99 k1500 suburban and the fan for the heater is not working. Here is what was happening when it finally did die. It would not come on for a few hours then when it did come on with the switch on high it blow at high
speed, but when I would go to change to a lower speed it would not work at all again. Then some times I could turn the truck off and on and get it to work. Now it doesn't come on at all. I checked the connectors and they all seem to be tight. The back heater fan controls work fine its just the front that doesn't work any more. Does this sound like it's the switch? Is there any way to test the switch to see if it bad.
I was going to go ahead and buy another switch but at $175 bucks I figure I might need to find out for sure before I start just replacing things.
Thanks for any advice
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Check for a burnt fan connector by the fan housing. This was a problem on earlier years, and I had a similar problem. Check behind the glove box and look for a connector wrapped in foam insulation between the fan and the Evaporator housing. THe main relay is usually on the very top of the evaporator housing to the left of the glove box.
Cheers

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Have a 96 that the switch did the same thing, replaced it and it went out again in 6 months, I replaced the fan motor as it would heat up the switch and burn the switch contacts. Tore the old switch apart (1st one) cleaned it up and still works fine. Look at the connection on the switch for melting. David

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problems with heater fan control switch Group: alt.autos.4x4.chevy-trucks Date: Wed, Dec 17, 2003, 2:38pm (CST+6) From: snipped-for-privacy@REMOVEprodigy.net (kdm75) I have a 99 k1500 suburban and the fan for the heater is not working. Here is what was happening when it finally did die. It would not come on for a few hours then when it did come on with the switch on high it blow at high speed, but when I would go to change to a lower speed it would not work at all again. Then some times I could turn the truck off and on and get it to work. Now it doesn't come on at all. I checked the connectors and they all seem to be tight. The back heater fan controls work fine its just the front that doesn't work any more. Does this sound like it's the switch? Is there any way to test the switch to see if it bad. I was going to go ahead and buy another switch but at $175 bucks I figure I might need to find out for sure before I start just replacing things. Thanks for any advice
Its no in the switch....Next to your fan you will see a electrical connection....That is you speed resistor.....Its held in by two 5.5mm screws...Unplug it and pull it out..9 times out of 10 you will see it burnt up....That is your problem...Ive had to change 6 just this week...Very common problem....The resistor has a green coating on it when you pull it out if the coating is peeling off or discolored ...That is it ...Replace it and all will bwll... Steve C
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Thanks for every ones help, but wife went ahead and took it to the dealership (she was going outa town and thought heat would be good on her trip ) they replaced the fan controll switch and a conector that went that it pluged into and some other work to the harness.

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