'96 Plymouth Voyager

[Rayna]

My Van has about 90,000 miles and runs good. The heat worked great last year but is just blowing cold air out this year. I do not know where to start looking for the problem. I do not have a over-heating problem and it blows air out just as strong as before this problem. I had to replace the battery last month, could that have anything to do with this problem?

[jdl]

Have you tried an in-vehicle calibration?

[Rayna]

I have never heard of such a thing but I will give it a try, thank you for your help!

[Spit]

First: Check your coolant level make sure it is full. Then check the pipes/ tubes at the firewall that deliver the coolant to the heater core, They are 2 different sizes I think I think the larger diameter one is the supply side and the smaller one the return. This will tell you that the warm coolant is getting to the heater core... If one of them is hot and the other rather cold, you could have a stopped-up /blocked heater core. Sometimes you can clear this up by backflushing the heater core. .

You might also have a baffle or duct-door for the blower that is not opening or closing. The duct door has to be in one postion for heat and another for AC..the calibration that was discussed has to do with the computer...making sure it is in synch for the right temp settings

Spit