While driving around I noticed that a burnt smell was coming from the ac vents. I found that a melted resistor was the problem. I swapped out the blower motor resistor and the blower motor which I assumed, as is usually the case, was drawing too many amps and caused the resistor to burn up. After swapping those out, the new resistor started smoking as well. I tried, as best as I could, to find a short in the wiring but could not find anything. Has anyone had a similar issue? Thanks for any help on this.
Blower motor resistor smoking
- Thread starter Tj Marc
- Start date
Odds are that some of the wiring in the motor/switch/resistor pack/wiring circuit got hot enough to melt the insulation so it is now shorting together somewhere. Time to get deep into all that and find the short(s).
The most common locations for the melted wiring are the harness connector at the resistor pack and the speed selector switch....
As recommended by JB; do a thorough inspection of the the harness connectors and their wires...
As recommended by JB; do a thorough inspection of the the harness connectors and their wires...
Not to hijack a thread, but I had a blown resistor. Plugged a new one in from mopar. Behold! All 4 speeds. Thing got very hot in the short amount of time I checked stuff. Talking less than a minute. I know they heat up, but that seemed hot hot. I am assuming this means the blower is drawing too many amps.
I guess the next step for me is to test the blower draw. Anyone have any info on how to do that? I can't find anything definitive on how many amps I should read on high. Sounds like 23 is normal based on a few other posts. But I feel like I also heard 15 and 20+ is a sign of a bad blower motor.
I guess the next step for me is to test the blower draw. Anyone have any info on how to do that? I can't find anything definitive on how many amps I should read on high. Sounds like 23 is normal based on a few other posts. But I feel like I also heard 15 and 20+ is a sign of a bad blower motor.
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That's a good question. I looked through your '06 FSM & didn't see anything definitive. Makes me want to test my own for a baseline but I have too much other shit to do. If anything I'd check resistance on the wires from the resistor connector to their termination, if you get anything more than an ohm or so then look at a wiring repair. If the resistance seems good maybe look at replacing the blower & compare the winding resistance with the new unit.
The usual cause of a blown resistor pack, burned switch, or melted wiring insulation is the fan motor. Its windings are insulted by shellac which can start breaking down and allow the windings to short together. Though it's also normal for the older design resistor pack to get very hot when the fan is running on its 3 lower fan speeds. The older design has a protective perforated metal shield that surrounds the hot resistors.
Thanks Jerry. Not what I want to hear exactly. Guess my next move is asking for opinions on after market motors. OEM price is just a little too high for my taste.
And I found many a thread with that. I swear, I have the hardest time finding anything in here with the forums search functions.
Are you using the Google search? The native search function blows. When you click on the search field a box will drop down & there’ll be a little “G” symbol. Click on that & then search for something. It’s much better.
JKP
TJ Addict
Not to totally bring back an old ghost thread here, but I just blew a two month old resistor. (It was blown when I bought it)
I think I'm just going to replace the motor and resistor this time.
I'm also going to check the :
Selector Switch
Wiring between the motor/switch/resistor
Try to blow out the air ducts
Is there anything else I should look out for?
I think I'm just going to replace the motor and resistor this time.
I'm also going to check the :
Selector Switch
Wiring between the motor/switch/resistor
Try to blow out the air ducts
Is there anything else I should look out for?
I’m a newbie here, so really sorry for resurrecting this old thread if I’m not supposed to. Just seemed a lot more sense than making a new thread for the same issue. A couple years back, my vents had smoke coming out with the fan on. Went away when I turned the fan off. I removed the resistor pack under the glove box, and found it packed full of twigs and leaves, mostly burnt. Cleaned it out and vacuumed out the duct, and no problem anymore until this week. Opened it again and found same issue today. Anyone else have this problem in the midwest? Not sure how all this debris is getting in.
Dan
‘97 TJ 4.0
Dan
‘97 TJ 4.0
The HVAC box is open to the cowl between the hood and cab...super easy for debris to make it in.
Couple of folks have rigged up filter housings. A in cab air filter if you will.
-Mac
Couple of folks have rigged up filter housings. A in cab air filter if you will.
-Mac
Thanks to both maclean and GE for your suggestions. I’m gonna look into both of those, to see if they’d be easier than attaching some heavy duty window screen to the underside of that cowl cover. I could see the cabin filter being worth it if I drove it more often. Maybe the cowl scoop. Thanks again.