Heater Problems

I have a 2001 Montana with Heater Airflow problems. There is plenty of heat and all the blower speeds work but the front and side windows fog up and eventually freeze.I dont know if the vents are shifting/opening properly.My other vehicles would fog up like this only when the heater was on recirculate.if I open the rear windows the rest of the windows will clear but it gets a little cool. If you put your hand in front of the heater vents you feel hardly any airflow.I tried removing the in cab airfilters,didnt make much difference....any ideas??

I'm wondering if you ever found the source of your defrosting problem? We just bought a 2002 Montana and are having the exact same problem. Lots of noise from the heater indicating the fan speed increases as expected, but very low airflow. Anything below freezing and the windows frost up like crazy...even the windshield doesn't always stay clear! I'd appreciate any suggestions you may have>

The two things that I would check would be if you coolant system is filled/air bled out completely, and are the air deflectors operating correctly. To see about the latter, you'll have to remove everything to get up to the heater core.

The two things that I would check would be if you coolant system is filled/air bled out completely, and are the air deflectors operating correctly. To see about the latter, you'll have to remove everything to get up to the heater core.


Hi....Lots of heat....no problem there.
Apparently the air deflector sticks to the foam seal causing it to stay in the recirculate mode.once it is freed up and sprayed with silicone spray it should work fine.

If the air flow is weak, check the cabin air filters. I change mine once a year just like the engine air filter. Good Luck...