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Heat/AC fan blower motor

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Old 04-21-2009 | 03:02 AM
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Default Heat/AC fan blower motor

My fan only works on hi. I traced the problem to the motor speed control resistor (I think thats what it's called). It has 3 wires and a ground hooked to it on the passenger footwell area. The plastic connector and ground were melted and not making contact. I stripped and replaced the charred wires and hooked it up. All fan speeds work but the problem is that the same wires get extremely hot in just a few seconds. I'm guessing the resistor is bad or the blower motor is drawing too much current on low and medium settings. My question would be how to check these 2 components for current draw or resistance.
Old 04-21-2009 | 06:51 AM
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Originally Posted by chip
My fan only works on hi. I traced the problem to the motor speed control resistor (I think thats what it's called). It has 3 wires and a ground hooked to it on the passenger footwell area. The plastic connector and ground were melted and not making contact. I stripped and replaced the charred wires and hooked it up. All fan speeds work but the problem is that the same wires get extremely hot in just a few seconds. I'm guessing the resistor is bad or the blower motor is drawing too much current on low and medium settings. My question would be how to check these 2 components for current draw or resistance.
That's a common issue.

First problem: the fan is drawing too much current as it ages... buy a new one.

Second problem: the connector is melted... buy a new "pigtail" connector and solder it in.

Third problem: the blower resistor terminals have overheated and are blackened... buy a new blower resistor.

So... a new fan, new resistor, and solder-in a new connector.

Otherwise you will be doing it again by the end of summer.
Old 04-22-2009 | 02:07 AM
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Yeah thanks, the resistor is about $35 bucks and easy to change. Have not priced the blower motor yet or looked into the amount of work to change out. Any tips?
Old 04-22-2009 | 04:00 AM
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put a resistor block in there and use a resistor for each fan speed.

jp magazine did an article on this a couple years ago.

my tj does the same thing. some catch fire, so a few bucks now will save a headache later.
Old 04-23-2009 | 11:41 AM
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OK, I bought a new resistor and blower motor. Where the heck is the blower motor at? Do I have to dismantle the entire dash like I suspect? Is it a week long project? Thanks for all the input.
Old 04-23-2009 | 12:29 PM
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^under the hood, passenger side, on the firewall. big black round thing.
Old 04-24-2009 | 01:21 AM
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Ha ha ha ha ha ha ha ha DUH, here I was up under the dash inside looking for it. Thanks.
Old 04-24-2009 | 08:40 AM
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hehe, no problem.
probably would've been the first place i would've looked also.
Old 05-18-2009 | 12:33 PM
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I'm having a similar problem. Tore into it today, and checked for voltage to the resistor. No power there. Fuse (#5 30Amp) is good. I'm assuming that I have a problem in the switch itself.

It's a '95 btw.
Old 05-18-2009 | 02:34 PM
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Originally Posted by ballistic_ken
I'm having a similar problem. Tore into it today, and checked for voltage to the resistor. No power there. Fuse (#5 30Amp) is good. I'm assuming that I have a problem in the switch itself.

It's a '95 btw.

Think I have the same problem. The fuse is lasting for 5 sec and the motor is new and the resistors are ok. Disconnected the resistor so the fan was runnig for full speed, same problem. Anyone changed the switch or plug ?
Seems to be a BIG job....
Old 07-28-2009 | 01:18 PM
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Originally Posted by chip
Ha ha ha ha ha ha ha ha DUH, here I was up under the dash inside looking for it. Thanks.
CHIP, How did your project go? Is it fixed? How much for the Blower motor and resister??
Old 07-29-2009 | 04:15 PM
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i am having promblems with my pigtail to the blower motor resistor they are getting hot and the ac keeps turning off
Old 07-29-2009 | 04:43 PM
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just wrote on another guys page who his only worked on 4... same problem... happens on all vehicles really... motor burns up and over heats the resistor... most dummies replace the resistor only and then burn it up again... course by this time autozone wont take it back cause its been installed your there screwed buying another... replace them both at the same time... not one now and one when you get the money later... got to a JY to get the plug... plugs are hard to find that match up at a new parts store... just cut it out of a old cherokee...
Old 08-02-2009 | 02:56 AM
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Originally Posted by GNon18s
CHIP, How did your project go? Is it fixed? How much for the Blower motor and resister??
Yeah, the resistor was about $35, a new motor about $40. You must replace both. The labor is a piece of cake. The pigtail connector to the resistor was slightly melted as well. I found one at the junk yard for a buck and spliced it in. There are different pigtails, make sure you get the right one. Good luck.
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