Originally Posted by BIRICON
I have an 03 Rubicon. My fan won't work on the first 2 low settings but will work on 3 and 4 - the two higher settings. I assume this is also the same resistor/switch type of problem? Also what is the relay mod that may eliminate all of this?
Also, isn't there some 'special' tool needed to remove the black bezel over the center dash section?
Your resistor pack is probably out. The problem is with the design of the wiring of the HVAC system. As your blower motor wears it pulls more current, totally normal. JEEP for some reason and GOD only knows, decided it was a good idea to have a 10 amp switch control a 30 amp max motor, Dumb A's. The relay is installed between the switch and the resistor pack/blower motor. The relays are rated for 40 amps so they can handle the current the blower motor will ever put out without blowing the fuse. So what we have is the switch controls the relay and the relay controls the blower motor. It's basically a protection device for the switch and resistor pack. Once installed you will never have a problem again, unless the blower motor actually goes out. Or at least I haven't in the past 6 or so years. I was replacing resistor packs and speed switches every few months. Thank GOD no more. Some will say just replace the blower motor, which will fix the problem until that motor starts to wear and that under rated switch begins to fail again.
A phillips screwdriver and 3 screws to remove the front bezel, 4 more screws to remove the speed/mode switch console, is all that is necessary to gain access to do the mod. Need to be able to solder and have tops of 45 minutes to do it. Simple and very easy to do. I have done it now about 24 times.