Ok, here's what it happened. Driving down the road and turned on the a/c. It blows nice and cold. Turned the fan switch up and the fan won't go up it only blows on the lowest setting. Up until this time it had worked fine. I pulled the resistor and it "Looks fine". The a/c blows cold, the heat blows hot. tried to pull the fan switch out of the dash with limited reults, couldn't get it all the way out. checked all fuses and only foun d a 5 amp that was blown, replaced it, not sure what it was for.
Also cruise doesn't do anything, didn't when I bought it a month ago. Everything else seems to work fine. No power windows or locks, seats etc.

It is a 94 cherokee sport police special.

 

The highest setting doesn't work either?

 

Nevermind about my comment.

 

I'd start with testing the switch if the highest setting doesn't work either.

 

You can check the resistor by checking for continuity across the diode, in boht directions. Should only have continuity in one direction. Mine went in my Jeep. I installed a new one and it immediately blew. I looked at the resistor and it looked fine; I put my meter across it and that told a different story. You could also check your voltages at the fan control harness, to make sure they are all getting power. HTH!

 

I had the same problem with my 91 XJ. the problem was the blower switch. on the high setting, it by passes the resistor network and a straight 12vdc goes from the battery through the contacts of the switch and straight to the blower, my high setting was burned up so all I had was the med. and low setting. I hope this helps.

 

More then likely it is your switch. If it was the resister it would only blow on high. When they fail it defaults to high.

 

Thanks for all the help guys. It was the blower motor switch in the dash. It was pretty burned.