JamDeeper

89 4.0 5speed. 333k miles.

The other day while driving (stopped at a red light with blinker on, foot on brake, blower off), let off the brake to go and the sun caught some smoke good enough to catch my eye, coming up from under the headlight switch. I'm most certain its not from there, but from my ignition switch. because, surprise, this has happened before.

Probably 3 years ago, now. I had to replace my ignition switch after a smoke out and dead jeep. pulled it out and blah blah blah you know what it looks like.

Problem is, here we are again. i found that the blower regulator switch was burnt and shorted after i had replaced my switch last time. which made me think that was my hole issue.

It wasn't.

My blower works on all levels (low to high). but if i have it on anything other than low, it (the "vent selector") gets HOT. I've learned to just leave it on low. until one day i replaced it with a JY one... Same thing. its low or electrical hot...

After the smoke the other day, i found that the brown wire looks like its hurting again. BUT WHY???? where do i start? What causes this?

everything works.. i just don't want it to keep burning wires.

I want to find the root cause. Because after searching in plenty of places, I am yet to find a legit fix.

Turbo X_J

Marginal wiring & cheap parts, it is what it is. Jeep never intended for your ride to last more than 4 years anyways.
If you are so inclined figure out the load for a given circuit a use appropriate wiring and relays can be used to lessen the load on switches. One thing to look at, excessive resistance burns up components too.

DFlintstone

Mine, with the blower speed switch "off", it still runs on low. I need to slide the top selector all the way left to "off" to actually stop the blower.

Now and then an electric motor, (like the E-Fan in a tempo I had), will continue to work OK, but start using a nutty amount of current. I did a bypass with my own relay on the temp switch there....after blowing 40 Amp fuses I finally figured out it was that motor, sucking way too much current!

I'd suspect that motor would get pretty warm if that's the case. Easy enough to check, see if it seems unusually warm, with the selector on defrost and the speed all the way down. Of course it might take a bit to heat up.

cruiser54

The switches are weak.

The Brown wire needs to be refurbished when the new switch is put in.

JamDeeper

So this will be something I do every 3 years? I "refurbished" everything the last time I replaced it. I'm just hoping to get some common findings causing this. Whether the blower gets old and needs replaced, or what. I don't want to have to do it again.

cruiser54

No. Not every few years. Just making sure it's been done.

How much is a blower motor?

JamDeeper

$40ish. Is it a deusy? Would it make sense to do if it is functioning perfect?

cruiser54

Easy to change. How do you know the blower cage isn't full of crap and creating an extra load?

You can view that from under the passenger side dash if you do things just right.

JamDeeper

I'm not saying it isn't likely. But it seems to be putting out sufficient air. It's never crossed my mind that it could be lagging.. I'll take a look see. Is there a known diagram I can chase through? I'm wondering if there was something spliced somewhere. The PO didn't really seem to be an organised "electrician". Most of the wiring in this thing is quite sloppy..