My 2000 Olds Bravada's heater is working weird. The heat comes on and blows warm air then I hear a slight noise from under the dash then it blows cold. Again after 2 or 3 minutes the heater blows cold. Then warm again.

The dash gauge shows the temp is correct, the anti-freeze is full at the radiator.

Thanks

Rich

That is a weird one but it might be that your heater core is either stopped up or getting stopped up, since its not leaking then we can pretty much rule out that it's the heater core is out, try flushing the heater core and see if that helps. And check for any leaks, since you said that the anti freeze and everything is full, I'm pretty sure that there's no leak.

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Originally Posted by richard gabrisch

My 2000 Olds Bravada's heater is working wierd. the heat comes on and blows warm air then I hear a slight noise from under the dash then it blows cold. Agin after 2 or 3 minutes the heater blows cold. Then warm again.

The dash gauge shows the temp is correct, the anti-freeze is full at the radiator.

Thanks

Rich

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I tried that, or rather my mechanic tried that. No help. If I turn on the AC the same thing happens - warm then cool, warm then cool.
I am going to have to find some with a computer tester.
Thanks for your suggestion
Rich

The door accuator on the box is shorted out and it keeps chaning from heat to cool

Check your coolant level, if it is low you will get that hot and cold air cycle. I have had this same problem and found it by mistake. It is also the cheapest fix.