Sir, with what you've seen, with passion, and know from tracing all the passages and settings; I am working on a 1999 Montana that will not stop bleeding hot air year around: the heat floods the A/C and it will not cool the van; I thought and hoped it was a bad control head on the dash OR actuator by the gas pedal; The actuator is working and moving 90 degrees; ; HOW DO I SHUT OFF CONSTANT HEAT TO STOP DEFEATING THE A/C based on messed up engineering ??
I have a 2001, I charged the ac, it worked until the day I put it on heat, now no matter what it seems to be stuck on heat, hot air comes out even when it's off, and turned to cold, and the controls won't change anything from the front vents to any other setting. What should I do?
Remove the kick panel driver side and passanger side and see if can see the servo motor for the blend door. Chances are motor went bad. Replace the servo motor. Should work Hopefully you can get to it by removing some interior trim peaces, otherwise you might have to pull out the whole airbox like i did. I wish you luck. Let me know how it goes.
In most climates that is enough to keep the windshield defrosted In northern regions of Canada its never enough. Gm knowing they were going to sell this vehicle north of the boarder should have done a better job designing the hvac system. Sadly they did not. At least not on the pontiac montana.
@@mechman4 I noticed that some configurations duct air under the seats to the back passengers and then the auxiliary heater in the back has vents that blow forward to the front seat from the ceiling. I wonder if this explains the weird configuration in your duct work. It may be that they expect the driver to control the auxiliary heater for their comfort.
hello, turning a Pontiac Montana into a camper, and I'm struggling to get the HVAC out. 5he entire dash is out and it's all that's left, besides the rear HVAC system, any tips, or recommendations for build ideas and removal of the front HVAC system,
@@michaelgrantham5344 yes but all the Pontiac products from 1999 to 2005 share a lot of the same parts the HVAC is very similar and dose share some the same design and parts
I have an '03 Venture with the same problem. I thought there was trash in the system because the van had sat up for several years under some trees, but no! GM engineers come through again! Bastards. I guess I'm just going to freeze.
Did you check the air cabin filters located behind plastic cover in glove box. Those filters get clogged and need to be replaced every so often. In the winter i would just remove them outroght. This will help improve your heating sotuation this winter.
Maybe the servo motor might be the same, but the box and door assembly, i highly doubt it. Manufactureres source parts and sometimes sub assemblies from same suppliers but design assemblies in house specofic to their vehicles only.
I sure hope I don’t have to go so deep when I get to work on the 2000 year model since it looks largely the same. Taking out seats and steering for this is way beyond what I’m willing to do. :)
One of the servo motors for air box is accesible from driver side. If your noticing air not being dorected when you switch dial or air temperature from hot to cold. you can remove servo motor from box still installed and seats in place. Just remove the driver side front panal to gain access to corner of air box that has this servo motor on it. Not sure if this servo motor is temperature motor or door flap motor for directing air. Cant remember.
@@mechman4 Thanks. I know the Fresh/recirculate actuator is by the windshield vent under the upper dash trim piece, so I think the one under the wheel is the blend door actuator. Thanks!
@@mechman4 Thanks again for your help. I replaced the source door actuator so it works and no longer just clicks when I switch between Fresh/Recirculate. I can see that the blend door actuator is turning the blend door just fine when I turn the Hot/Cold knob. Unfortunately, I don’t get anything out of the front vents and I can’t seem to redirect the air no matter what I have the knob set to. This means I still have a problem with the mode door or mode door actuator. It seems they switched from vacuum to electric mode door actuation in 2001 and mine is a 2000. I can’t seem to find any info about where the mode door or the actuator is for the 2000 model. It’s maddening! Looks like I might have to do a deep dive like you after all. :(
@@emmettturner9452 Sorry to hear about the future project ahead of you. But take heart. If you have cordless tools and air tools, tearing apart the inside of your van, although allot of work can be done in a weekend. Make sure you have all your replacement parts ready to go so your vehicle doesnt sit out of comission while you wait on parts. I would recomend replacing your heater core and hard to reach servo motors if your going to go into this disasdembly. You dont want to be doing it twice because your heater core later fails down the road.
Sir, with what you've seen, with passion, and know from tracing all the passages and settings; I am working on a 1999 Montana that will not stop bleeding hot air year around: the heat floods the A/C and it will not cool the van; I thought and hoped it was a bad control head on the dash OR actuator by the gas pedal; The actuator is working and moving 90 degrees; ; HOW DO I SHUT OFF CONSTANT HEAT TO STOP DEFEATING THE A/C based on messed up engineering ??
Is your a/c circuit charged with refrigerant ?
And
Is your a/c compressor kicking on with ac switch at head unit pressed in ?
I have a 2001, I charged the ac, it worked until the day I put it on heat, now no matter what it seems to be stuck on heat, hot air comes out even when it's off, and turned to cold, and the controls won't change anything from the front vents to any other setting. What should I do?
Remove the kick panel driver side and passanger side and see if can see the servo motor for the blend door.
Chances are motor went bad.
Replace the servo motor.
Should work
Hopefully you can get to it by removing some interior trim peaces, otherwise you might have to pull out the whole airbox like i did.
I wish you luck.
Let me know how it goes.
Maybe it’s because hot air rises anyway. That’s why I always manually direct hot air to the lower/floor vents in any car that lets me.
In most climates that is enough to keep the windshield defrosted
In northern regions of Canada its never enough.
Gm knowing they were going to sell this vehicle north of the boarder should have done a better job designing the hvac system.
Sadly they did not. At least not on the pontiac montana.
@@mechman4 I noticed that some configurations duct air under the seats to the back passengers and then the auxiliary heater in the back has vents that blow forward to the front seat from the ceiling. I wonder if this explains the weird configuration in your duct work. It may be that they expect the driver to control the auxiliary heater for their comfort.
hello, turning a Pontiac Montana into a camper, and I'm struggling to get the HVAC out. 5he entire dash is out and it's all that's left, besides the rear HVAC system, any tips, or recommendations for build ideas and removal of the front HVAC system,
Have you removed the bolts on the engine compartment side of the firewall holding your hvac box in place ?
I think there are 2 possably 3 bolts.
I’m pretty sure there was a redesign because I have an 2004 Pontiac Grand Am and I get heat out of all the zones just fine
I imagine your right.
Just my luck I bought a 2002. 2003 or 2004 would not have been an issue.
@@michaelgrantham5344 yes but all the Pontiac products from
1999 to 2005 share a lot of the same parts the HVAC is very similar and dose share some the same design and parts
I have an '03 Venture with the same problem. I thought there was trash in the system because the van had sat up for several years under some trees, but no! GM engineers come through again! Bastards. I guess I'm just going to freeze.
Did you check the air cabin filters located behind plastic cover in glove box.
Those filters get clogged and need to be replaced every so often.
In the winter i would just remove them outroght.
This will help improve your heating sotuation this winter.
Funny, I have an 05 Montana and I have the same issue with cold air, heat flows fine from all vents.
does it have the same blender door motor type thing that toyota does?
Maybe the servo motor might be the same, but the box and door assembly, i highly doubt it.
Manufactureres source parts and sometimes sub assemblies from same suppliers but design assemblies in house specofic to their vehicles only.
I sure hope I don’t have to go so deep when I get to work on the 2000 year model since it looks largely the same. Taking out seats and steering for this is way beyond what I’m willing to do. :)
One of the servo motors for air box is accesible from driver side.
If your noticing air not being dorected when you switch dial or air temperature from hot to cold.
you can remove servo motor from box still installed and seats in place.
Just remove the driver side front panal to gain access to corner of air box that has this servo motor on it.
Not sure if this servo motor is temperature motor or door flap motor for directing air.
Cant remember.
@@mechman4 Thanks. I know the Fresh/recirculate actuator is by the windshield vent under the upper dash trim piece, so I think the one under the wheel is the blend door actuator. Thanks!
@@mechman4 Thanks again for your help.
I replaced the source door actuator so it works and no longer just clicks when I switch between Fresh/Recirculate. I can see that the blend door actuator is turning the blend door just fine when I turn the Hot/Cold knob. Unfortunately, I don’t get anything out of the front vents and I can’t seem to redirect the air no matter what I have the knob set to. This means I still have a problem with the mode door or mode door actuator.
It seems they switched from vacuum to electric mode door actuation in 2001 and mine is a 2000. I can’t seem to find any info about where the mode door or the actuator is for the 2000 model. It’s maddening! Looks like I might have to do a deep dive like you after all. :(
@@emmettturner9452
Sorry to hear about the future project ahead of you.
But take heart.
If you have cordless tools and air tools, tearing apart the inside of your van, although allot of work can be done in a weekend.
Make sure you have all your replacement parts ready to go so your vehicle doesnt sit out of comission while you wait on parts.
I would recomend replacing your heater core and hard to reach servo motors if your going to go into this disasdembly. You dont want to be doing it twice because your heater core later fails down the road.
I have a 2005 pontiac Montana and it does the same thing