I was wondering if anyone else had this problem and what it was. My ac and heat will only work when the fan switch is on hi (4) the blower motor does not come on with 1, 2, or 3 just 4? Im thinking either a fuse or a bad fan switch. I havent had a chance to get my meter out or check the fuses which will be the first thing I do, lol.

 

You need to replace the resistor for the blower motor. It is located under the dash. Most likely on the blower box assembly.

 

Thanks, replaced resistor and all is good!