My fan is only working on the highest setting. I have a 2003 Dodge Ram 1500 Hemi 4x4. All the zones work properly, and the temperature adjustment dial works fine. But my fan speed (I have speeds 1-4) only works on 4 (the highest). About a month ago I noticed the fan going on and off as I was driving...now it doesn't work at all on the first three settings. Any clues on where to start trouble shooting? THANKS!!

 

I would suspect that you start with the fan selector switch and ensure all contacts are made. The fact that it went on and off suggest you may have a loose connection somewhere in the system. Check a component and resistence and work down the electrical path.

 

Had to replace the switch at about 70k previous owner was switch happy. Headlight switch went out at 90K

 

On my old Ford , there was a resister that went bad under the hood.

 

Weird...I was going to look at it this morning and its all working now. Hmmm, must be a bad connection somewhere. Needless to say, its about 20 degrees outside so I left well enough alone. I'll look at it when I have to. ha.

 

Well, it worked for a while...now it stoped. So I'm back onto fixing this problem. The same thing is happening, the fan speed selecter switch only works on high. I took it all apart and cleaned the contacts...no change. Any hints on what to do next? Does anyone know where on my truck the resistor is located?

Thanks.