latley I noticed that the rear heat/air only works on high. it seemed to be working fine a few weeks ago but now the low and medium fan speeds are dead. it is a 2003 grand caravan. could it be that the thermostat is bad or could it be a bad fan motor.

 

likely the rear blower relay. I think its around $15 or so at the local parts place and was told its fairly easy to change.

 

Most likely the rear resistor block or controller. If you have automatic temp control you'll have the later. If the relay was dead you would have no fan at all.

 

resistor is actually want I thought I said lol. I was tired.

http://shop.advanceautoparts.com/web...hTerm=resistor

 

ok thanks. will look into it. now where is the resistor located. and how hard is it to replace.

 

It's mounted on the rear of the rear HAVC unit behind the passenger side rear trim panel. Here's some pics: http://www.qsl.net/n/n9mxq//blower/ Again, if you have automatic temperature control then you have a solid state controller. I can only assume it's mounted in the same area. The bad news is they cost about 3 times what a resistor block costs ($10 - $40).

 

OK thanks. Don't think it is automatic thermostat. It is the dual zone thermostat where the passenger can have hot and driver cold or whatever

 

Yep. It's the resistor. I have a 2001 Grand Caravan and I've had to replace the resistor twice on the front system, which is mounted behind the glove box in the dash, and the resistor in the rear once, which is behind the panel on the right as viewed from the rear hatch. Later on when I had no fan speed at all on the front, I had to replace the blower motor. But when you have 'high' fan speed only, it's the fan control resistor.