Blower motor goes on and off

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corvette744

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So i go into the auto store come out and blower motor cuts off-hmm turned off and on nothing.Start driving kicks on for a second then off-does this 3 times till i get home.I am assuming the ac head unit since it on occasion when turning knobs doesnt go to the temp i want right away have to fiddle with it.Never been under the dash so took off lower panel under passenger side.Checking connectors all seem tight blower motor kicks in and out every couple minutes for a second then off.So im now looking at the resistor and notice a drop or 2 of moisture on it-take it out and its slightly damp.Pop cover off has tiny bit of corrosion on terminals and slightly damp.Blow out with air and clean terminals.Re install and all working perfect-just dont get how inside resistor its damp and has corrosion.Im getting a spare just in case it happens when its 20 below zero.
 

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rockola1971

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So i go into the auto store come out and blower motor cuts off-hmm turned off and on nothing.Start driving kicks on for a second then off-does this 3 times till i get home.I am assuming the ac head unit since it on occasion when turning knobs doesnt go to the temp i want right away have to fiddle with it.Never been under the dash so took off lower panel under passenger side.Checking connectors all seem tight blower motor kicks in and out every couple minutes for a second then off.So im now looking at the resistor and notice a drop or 2 of moisture on it-take it out and its slightly damp.Pop cover off has tiny bit of corrosion on terminals and slightly damp.Blow out with air and clean terminals.Re install and all working perfect-just dont get how inside resistor its damp and has corrosion.Im getting a spare just in case it happens when its 20 below zero.
Ill tell you exactly how you ended up with that amount of moisture in your ductwork. Your evaporator drain is plugged up.
 
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corvette744

corvette744

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I checked its perfect.Not a thing in it.Its freezing here lol haven't had the ac on in over a month.After further thought-i did run it thru the car wash about 30 minutes before i went to the auto parts store.So now im thinking a seal on the outside cowl might have a tiny gap that lets a drop or so just in the right place hit the resistor.So my plan is to go thru the car wash again with the resistor out and have a piece of paper in their.That will tell me if im right or not about the leak.Takes about 45 seconds to remove so i will let you know what i find.Also after reading about how many of these have the resistor wiring burnt and have a new updated resistor that you have to cut and splice in-mine did have that done already.Did not notice and burnt wiring or any signs of it.From what i read the factory blower motor draws to much amperage for the 3 wire resistor in these.The updated resistor comes with new wiring from resistor to blower motor and its 5 wire.Seems like gm new it was a problem and did not put out a recall.Some of the pics i seen the plug on the resistor caught fire and could of burnt the vehicle down.
 
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rockola1971

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You do know that during the cold season your A/C cycles on and off while you are in heat mode so the evaporator can remove humidity (moisture) from the inside of your vehicle, right? That moisture has to go down that drain. An Air Conditioner is a dehumidifier. Thats how it removes heat. Its the humidity that carries the heat. You could have indeed gotten water in the fresh air intake during your car wash but the corrosion didnt happen in that short of time.
 
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corvette744

corvette744

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You do know that during the cold season your A/C cycles on and off while you are in heat mode so the evaporator can remove humidity (moisture) from the inside of your vehicle, right? That moisture has to go down that drain. An Air Conditioner is a dehumidifier. Thats how it removes heat. Its the humidity that carries the heat. You could have indeed gotten water in the fresh air intake during your car wash but the corrosion didnt happen in that short of time.
Agreed the corrosion didnt happen after my car wash-and the ac cycle when your in defrost mode not any other modes.I can tell when the ac clutch engages.Also i noticed when its under about 30 degrees out the ac clutch wont engage so i assume is has a sensor either on the evaporator or its the pressure switch not allowing it to turn on.I have never felt the ac kick on in winter and i can feel it unless im in defrost mode,then it does since i have owned this tahoe.The drain is clean i made sure of that.The reason im thinking the car wash is the 12 hot air 100 mph dryers they have at the end forcing a small amount of water in somewhere and a drip on the resistor.I run it thru their 5 times a month or so.We will see next time thru.Not today its snowing out now
 
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rockola1971

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Agreed the corrosion didnt happen after my car wash-and the ac cycle when your in defrost mode not any other modes.I can tell when the ac clutch engages.Also i noticed when its under about 30 degrees out the ac clutch wont engage so i assume is has a sensor either on the evaporator or its the pressure switch not allowing it to turn on.I have never felt the ac kick on in winter and i can feel it unless im in defrost mode,then it does since i have owned this tahoe.The drain is clean i made sure of that.The reason im thinking the car wash is the 12 hot air 100 mph dryers they have at the end forcing a small amount of water in somewhere and a drip on the resistor.I run it thru their 5 times a month or so.We will see next time thru.Not today its snowing out now
You are getting snow in Northern IL today? What city?
 

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