Just got cold enough to discover some heating issues.

First issue - fan only worked on high. Changed out the resistor and now have all fan speeds - YAY!

Second issue, no heat. Luke-warm air only. I changed out the thermostat (good call as it was literally in pieces when I removed it) and we now have HOT air. However, it's intermittent. Hot air will change in an instant to cold, and then back to hot.

Any ideas? This is the 3.3L. Thanks!

 

possible air bubble in heater core area

 

We were thinking possible air in the lines somewhere, too. Could you point me to some directions how to remedy that?

Another thought... tonight when the heat turned to cold again, I started fiddling with the thermostat (the two slides marked from blue to red). As soon as I moved it back toward red, I heard a quiet thud and then heat again. Isn't there some sort of flap that opens to allow the air to flow to the heater core? If so, any idea how I can troubleshoot that?

 

Try the HVAC system calibration described here in post #7: http://dodgeforum.com/forum/dodge-ca...formation.html

If your A/C is not working don't perform this test. If it fails the A/C cool down test warm up the interior of the van and try again.

 

It worked! I did the calibration and my heat is working wonderfully!!

Thank you so much for your help!
Jennifer

 

Great news. By any chance did you disconnect or change the battery over the summer? Power interruptions seem to be a common cause for your type of problem.

 

No, I didn't. In fact, I replaced the thermostat without even disconnecting the negative lead (whooops).