2003 TJ 4.0 5spd. So the heater fan only works on the highest setting...nothing happening on the other three settings. Blower motor or the switch? Has anyone seen this before? If this is a common failure, it might save me some time on the troubleshooting side of things. Thanks.

The fan only working on high is normally due to a defective resistor pack. The resistor pack is used for all speeds except for the fan's highest speed where the resistor pack is bypassed. Your 2003 has it in a different location than my '97 does but yours should be somewhere up above the passenger side footwell. It's easily swapped.

Sweet! Thanks for the heads up! That definitely gives me a head start on the troubleshooting. I'll take a look at the service manual and see wherethe resistors are. I'm sure I can check the circuit with a DMM.

It's not a traditional set of resistors like you may be thinking of. In newer TJs, it's more like a credit-card size plug-in which can't be repaired.

The blower resistors are on the passenger footwell right behind the glove box on the blower housing. Mine problem ended up being the blower motor selector switch.

Gotcha. I wasn't expecting a bank of axial lead components but I wasn't sure what to look for either. Thanks. I expect it's a pluck and chuck situation.

Yep the resistor look like a large relay.. Just unplug the old one and install a new one.

I have the same proble here as Hondarider... ONLY the high speed is working on my blower motor. I checked the switch selector with a multimeter, and I think the switch is ok..according to a continuity test.
I have 97 wrangler... I har it can be the resistor? Where is it? what does it lok like?
Thanks for your help
jake