Question about 1999 Pontiac Montana

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2000 pontiac montana is not blowing hot air.

I have replaced the thermostat, engine coolant and climate control module. I have also looked into the heater selection flap driven by an electric motor in the heater box and I am satisfied it is working. I have noted that the auxilary coolant pump for the heater core is not working and have hard wirred it to a switch. Even with it hard wired the van still does not blow hot air. I am satisfied that there is cooland passing through the heater core as both hoses are hot and feel as though there is movement. My questions are: Where is the switch that controls the auxilary coolant pump, from the schematic it is feed from a fuse witch is good, to the switch then the pump.
I have also read that there is a chance that the problem could be a programing failure in the powertrain control module after a thermostat fails. That would suggest the module needs to be reprogramed. I dont get it, does that seem practical? My last question is what is wrong with this van...please help

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  • drfallis Dec 18, 2008

    our 1999 pontiac montana heater is not working. He has flushed the system out and it still is not heating up. He replaced the thermostat also. What could this be?

  • Anonymous Dec 31, 2008

    We have no heat as well in our van. I was hoping it would be a simple fix, perhaps a thermostat, but I am a little worried now after reading this thread! Anyone find a solution?

  • Anonymous Jan 16, 2009

    please? Do you know how to get heat inside



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It seems to be the only thing left would be the heater core replace that and see if that works here to help Shaun

Posted on Nov 16, 2008


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1 Answer

2000 pontiac montana blows cold air but does not heat up

Check your flapper doors and blower/ducts for clogs or problems.
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2003 Pontiac Montana heat gets hot in front, blows but seems weak, and no heat on rear controls but blows ******* rear. what is going on?

Is your heater blower motor working on all speeds ? Are you get any air coming from the rear vents ?

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My 2000 Montana gauge is showing that's over heating even when it's driven a short distance and when driven on the freeway it's not smelling like its over heating or there no steam coming

If the gas gauge does not work correctly and the temp gauge reads hot, you could have a problem with the instrument panel.
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If the temp gauge is reading correctly, you could have air in the cooling system and it is not actually full of liquid coolant.

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My 2000 grand prix blows out cold air when its on heat

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I have a 2000 pontiac Montana. The problem is with the coolant

We have the same problem. It's an air pocket in the cooling system. The cause can be anywhere from not filling the system all the way or most likely a leak has developed and air has entered into the system as the coolnt level has dropped. The coolant light goes off and on as the air pocket moves around.

Our Montana has a leaky intake gasket, which is the source of the problem. A very common problem with the 3.4. It should go for another 100K plus though, once it is repaired.

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I have a pontiac montana 2000 my problem is i dont have warmth in front of in my heater and behing it is very warm

There are a couple of possible problems Carole.
First one is there may be a blockage inside the heater core causing poor flow of the coolant from the engine which gives you the heat.
If this is the case the core will need to be flushed out or possibly replaced.
Second problem may be the door that is supposed to move inside the heater box that changes the air flow from cold to hot may not be working properly. The controls may be defective or the door is seized.
Because your heater in the back is working well the thermostat and the coolant level should be OK.

Jan 23, 2010 | 2000 Pontiac Montana

1 Answer

2002 Pontiac Montana, No Heat, I put the temp control on

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Heat blowing cold air in 2004 chevrolet suburban

With coolant full and engine hot,make sure both heater hoses are hot. If not replace thermostat. If they are, check the blend door for proper operation. Otherwise you may have a bad climate control module. Check both front & rear units.

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your radiator may have frozen the thermostat

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1 Answer

2005 Pontiac Montana SV6 heater blows cold when slowing to idle

How cold is it there and does your engine cool down any while going slow? If it does it may mean you need a hotter thermostat installed, My first thought would be to check the coolant level in the radiator and the coolant reservoir! Hope this helps and Merry Christmas

Dec 23, 2008 | 2005 Pontiac Montana

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