hi I have a rendezvous 2003 and I just change the heater core and now I'm having problems air blowing on the passenger side in heat on the driver side but only when you have it on defrost
2 Answers
Sounds like the blend door(s) are not opening or closing all the way. When the core was changed, the door might have something in it's way, like a wire from under the dash. If you had a mechanic fix it take it back and have him take a look at it. He should fix it at no charge, if he's any good.
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