Blower switch problems


rebeldad
08-12-2007, 06:32 PM
I have a 99 Jeep Wrangler Sahara and this morning I went to turn down the blower from high to medium and the whole thing quit blowing. I have discovered that if you put the switch between high and medium at a certian spot that the blower will blow on medium. Is it the switch or the blower motor relay( or resistor, dont know what it is really called? Thank you for any help...

scoobytuff
08-13-2007, 10:52 AM
You can get just the switch from the dealer. I bought one and it was less that $20. You will want to do that pretty soon because the back of the ac control panel is probably getting pretty hot. Mine was almost too melted to use. I ended up being able to reshape it enough with a file to make it work. For some reason the contacts inside the switch cause a bad short. Check it out, I bet that'd what it is.

tgrif
12-01-2007, 05:28 PM
I have the same problem. How do you replace the switch?

scoobytuff
12-02-2007, 12:15 AM
First you'll have to pull off the bezel that goes around the HVAC controls and radio. The whole thing comes off, the two vents in the dash included. The vent cover right next to the windshield just snaps off. There are a couple of screws under there (maybe just one, I haven't pulled it off in a while). There is also a screw behind the ashtray, so you'll need to pull it out and set it off to the side. When you get the bezel off there are some screws that hold the heater and air conditioning controls in. After you get that out its pretty much plug and play. BTW, the knobs on the control panel pull straight off. I've pulled them off with pliers but that can really scratch the knobs up. A better way is to gently pry the knob off. Everything is pretty straight forward once you pull the controls out. Check the wires really good and make sure that none of them are chaffed or that the insulation isn't burned off of them. When you have the new switch in your hand it will make sense to you. Everything goes back on in reverse order of the way it comes off. Don't force anything to come off or out. Find out where it's getting hung up and then go from there. Everything should come apart easy and go back together the same way. Good luck to you!

ccranger
12-05-2007, 07:56 PM
I replaced the switch 3 times and found that there are two that are affected. I have a 2000 Wrangler. I finally went to the dealer and had the wiring harness relaced and now have no more problems. Mechanic told me there is a problem in the harness. I tried looking at it with a meter but found nothing. Of course try shooting the problem without the right wiring diagrams. It's been a year now and no problems. The whole dash has to come out. They broke my windshield while doing the work and replaced it for free and also re-inspected the vehicle. What bites is that they know of the problem.
Good luck.

scoobytuff
12-06-2007, 01:40 AM
I have actually seen several people put relays in the wiring harness to prevent this problem. I have only had to replace my switch once so far and I've had this particular Jeep for a long time. There is really no 2 switches that are affected but the wire that goes from the temperature control to the hvac switch can get hot enough to not have any insulation. Once this happens it can become a mess. The main problem with Jeeps setup is the heat generated by the whole hvac control panel. This is where the relays come in. once they get too hot they will trip, then reset when there is not such a load. It's not as good a fix as replacing the wiring harness, but my Jeep is old and I have a hard time spending lots of money on stuff like that. I also don't like dealerships.

2000izusu
12-06-2007, 08:30 AM
this exact problem was just written about in jp magazine! they put relays in to fix it. according to the magazine the problem is caused by the blower motor pulling more amps due to the brushes in the blower motor getting worn with age. mike

scoobytuff
12-06-2007, 11:24 AM
I didn't see that particular article but JP magazine usually has really good tech articles. That magazine is probably the best magazine for a Jeep owner to get a subscription to.

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