Front blower motor not working.

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Recon189

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Greetings, I have a 2004 Tahoe Z71 with a non working front blower motor. My son, which drives the vehicle, stated that the blower motor just stopped working while going down the road. I began checking it out by checking all fuses and relays. All appear fine. I then pulled the blower motor out of dash and determined there was power to the plug at the motor. I bench tested the blower and it worked fine. I have power from the switch to the blower resistor and from the resistor to the motor. Plugging the resistor back in, plugging the motor into the resistor but the motor fails to work. I did notice that the power to the resistor and to the motor are constantly hot, don't know if that is normal.

So now my question is could the resistor be bad even though it is allowing power to go to the blower motor? Oh, the power plug to the resistor is only a three wire plug and I don't know how to test the resistor.

Any help would be greatly appreciated as I'm stumped on why the motor isn't working if it is getting power to it.

Thanks in advance for any assistance.
 

Doubeleive

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Greetings, I have a 2004 Tahoe Z71 with a non working front blower motor. My son, which drives the vehicle, stated that the blower motor just stopped working while going down the road. I began checking it out by checking all fuses and relays. All appear fine. I then pulled the blower motor out of dash and determined there was power to the plug at the motor. I bench tested the blower and it worked fine. I have power from the switch to the blower resistor and from the resistor to the motor. Plugging the resistor back in, plugging the motor into the resistor but the motor fails to work. I did notice that the power to the resistor and to the motor are constantly hot, don't know if that is normal.

So now my question is could the resistor be bad even though it is allowing power to go to the blower motor? Oh, the power plug to the resistor is only a three wire plug and I don't know how to test the resistor.

Any help would be greatly appreciated as I'm stumped on why the motor isn't working if it is getting power to it.

Thanks in advance for any assistance.
typically the resistor goes bad, its pretty common
 

Doubeleive

Wes
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Double level thanks for responding. If the resistor is bad will it still allow power to pass through it to the blower motor?
if there was enough power coming out of the resistor and the blower is known to be good then it would spin right?
the thing is it may show 12v but may only have .004 milliamp which would not be enough to spin the blower, the resistor will create heat which eventually just burns it's self out, this is why they generally have a heat sink on them so the blow-by air can cool the resistor but over time they eventually die anyway.
 
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Recon189

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if there was enough power coming out of the resistor and the blower is known to be good then it would spin right?
the thing is it may show 12v but may only have .004 milliamp which would not be enough to spin the blower, the resistor will create heat which eventually just burns it's self out, this is why they generally have a heat sink on them so the blow-by air can cool the resistor but over time they eventually die anyway.
I didn't use a multimeter I used a test light to check power on the plug. So I don't know how many volts is at the plug. I'll check it this weekend when I'm off and see what the voltage is.

Should the plug be hot even with the key off?
 

HiHoeSilver

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I didn't use a multimeter I used a test light to check power on the plug. So I don't know how many volts is at the plug. I'll check it this weekend when I'm off and see what the voltage is.

Should the plug be hot even with the key off?

I know it seems weird. There's another thread from the past year somewhere with the same problem. Iirc, he tore the controls apart and everything. It was the resistor. Save your time and just change it. If it doesn't fix it (probably will), you've got a new, known good part.
 
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Recon189

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I know it seems weird. There's another thread from the past year somewhere with the same problem. Iirc, he tore the controls apart and everything. It was the resistor. Save your time and just change it. If it doesn't fix it (probably will), you've got a new, known good part.
That's probably what I'll do I just hate to spend $115.00 and that not be the problem.

Thanks for your help.
 

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yellosno

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Greetings, I have a 2004 Tahoe Z71 with a non working front blower motor. My son, which drives the vehicle, stated that the blower motor just stopped working while going down the road. I began checking it out by checking all fuses and relays. All appear fine. I then pulled the blower motor out of dash and determined there was power to the plug at the motor. I bench tested the blower and it worked fine. I have power from the switch to the blower resistor and from the resistor to the motor. Plugging the resistor back in, plugging the motor into the resistor but the motor fails to work. I did notice that the power to the resistor and to the motor are constantly hot, don't know if that is normal.

So now my question is could the resistor be bad even though it is allowing power to go to the blower motor? Oh, the power plug to the resistor is only a three wire plug and I don't know how to test the resistor.

Any help would be greatly appreciated as I'm stumped on why the motor isn't working if it is getting power to it.

Thanks in advance for any assistance.
Had the same problem on my 2007 Yukon Check the connector pins. Mine was burnt at the motor end. GM wanted $$$ for a two wire harness but amazon had a delco. I managed to repair it.
 

camaroz1985

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Try the resistor. Just replaced our resistor (AC Delco on Amazon was $33 I think). Had a leak from the cowl that went down into the blower box and corroded the resistor. Replaced it and sealed panel above fresh air intake and all is good now except for high speed. I'm wondering if the motor itself is bad and just draws too much on high. I didn't check current, but resistor sends 12V to the motor in all speeds. Is the current varied or is it PWM for the different speeds?
 

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