On my 2005 Wrangler, the low speed fan setting does not work..Medium and high settings work fine...Could this be a bad relay and if so where is it located..or is it in the fan itself?...thanks for any info RKL
I'm doing mine, (2000tj), today. Same problem. It's the resistor on not only Jeeps but on vehicles in general. The heater motors are made to run on 12 volts when on high, and on less to run on the other lower speeds.
I renewed my resistor yesterday as I had planned, (napa part #257 for my 2000). I started by taking the glovebox door off which I didn't need to do, but it does let more light into the work area. You still can't see anything till you remove the thin black plastic cover from the assembly, (4- 8mm screws), and you'll see the resistor held in by 2 more 8mm's. Once removed from the air-flow you can better see to unplug it. Your old resistor could be cruddy looking because it's in the intake air-flow being cooled because it get's hot performing it's task .
If we imagine a day in the life of one of these resistor packs we can understand why they fail so easily. By the time we are arriving at a destination, the vehicle is comfy, the fan on low, the resistor assembly is at it's very hottest from it's job of converting volts into heat and dissipating it into the air and it is depending on the air flow passing by it to cool it off--and you shut the Jeep off. No more air flow. The temp of the resistor raises dramatically for a minute or two and I think I recognize a little capsule shaped heat-fuse sitting in there that is probably the cause of the failure. You'll see it too, it looks like a pill. They are cheap at Radio Shack and I'm going to replace mine and clean it up the assy with throttle body spray for future use. This is the same device that is in the nozzel of hair dryers so they won't melt. Do the resistor a favor by turning the fan off just BEFORE you arrive, (and run your hair dryer blower on cold for a few seconds).
Mine all cut out, I got my high to come back on be taking it apart, cleaning the switch, and pushing in on the rod that runs from the switch back in. the other three dont work, so I think I still need the resistor. but it seems that my switch may be bad too?
Ryan - A good eye, a light foot, and a smart rig. Bolt-ons are boring
When my resistor started to go, I lost fan speeds one by one over time starting with the lowest speed. My neighbor's TJ did the same thing.
Yeah, the pack has more than one resistor in it. What speeds don't work depends on which resistor blows. If the heater won't work on high, it's either the switch or motor. Anything below that, I'd look at the resistor pack first