Still Screwin with the A/C!

[forbey]

All right, it's been in the triple digits around here with the heat index above 110. My 95 Burb is still putting out massive quantities of HEAT!

I just replaced the module behind the glove compartment, without any luck.

I removed the 2 fuses in the doorway and clean what looled like varnish off of their prongs. THe large A/C relay in the fuse box under the hood. The prongs look just as bad; however, when I put it back into place, it didn't appear to grab hold (seems a tad loose.) Is there a way to spread the contact points of the received fitting to try and get better contact?

Someone sad something about a reset button? (Sorry, I'm burning up while expiring options.)

forbey

[rameye]

I'm not an AC guy...but I think it would be helpful if you posted what exactly is going on and what you have tried...be detailed...the more info you post the better chance of a solid response you have..

[forbey]

Sorry, I should have given the whole scoop.

When I bought the Burb in 2005 the A/C & heat would not work consistently. At times it would heat and some times it would blow cold. Some time the blower would work, sometimes it wouldn't.

As time went on, it got to a point that I could tell whether we were in winter or summer because the HVAC would run opposite to the season... YUPP! Heat in the summer, A/C in the winter.

It, at present has been stuck in "non-blowing heat" mode for over a year.

I replaced the control panel with a used one, no luck.

At a friend's request, I checked the module behind the glove compartment, replaced it for $25. Still stuck on heat.

It might be a ground wire, I've checked all the fuses. I can't seem to get to the actuators that control the doors on the system.

Either way, with temps in the high 90s lately, and the heat index between 100 and 110driving down the highway with all the windows down is brutal.

Still messing with it, learning a lot, not solving much!

forbey

[suburbanK-2500HD]

Sorry, I should have given the whole scoop.

When I bought the Burb in 2005 the A/C & heat would not work consistently. At times it would heat and some times it would blow cold. Some time the blower would work, sometimes it wouldn't.

As time went on, it got to a point that I could tell whether we were in winter or summer because the HVAC would run opposite to the season... YUPP! Heat in the summer, A/C in the winter.

It, at present has been stuck in "non-blowing heat" mode for over a year.

I replaced the control panel with a used one, no luck.

At a friend's request, I checked the module behind the glove compartment, replaced it for $25. Still stuck on heat.

It might be a ground wire, I've checked all the fuses. I can't seem to get to the actuators that control the doors on the system.

Either way, with temps in the high 90s lately, and the heat index between 100 and 110driving down the highway with all the windows down is brutal.

Still messing with it, learning a lot, not solving much!

forbey

Have you had anyone connecting a AC Service-Diagnostic unit to the car.
(those you fill R134 with).
It is helpfull to se if the system has fluid, and that the compressor it working properly. You can read the high and low pressure in on\off pos.
Are you shure the expantion valve is ok...If open iguess it would sirculate the heat in the system..

[Robyn]

This sounds like the "MODE" servo has failed

Also there could be an issue with the servo that controls the blend door.

These are not the easiest items to get to but doable. They are small back boxes that fasten to the HVAC box under the dash.

The control unit (dash control) sends electrical signals to these to open/close or whatever is needed to give the airflow to the desired position and at what temperature.

If the blend door is stuck in the hot position this would explain.

The mode control servo can also do this.

You need to get a GM manual for the truck and follow the diagnostics section on the HVAC system.


Missy

[Big Green]

I had an issue simular to yours, basically nothing worked. No fan, no hot or cold control, etc.

System checked like it had an open ground. I didn't have time or a diagram to really chase it down.

Ended up with the local dealer and he found a burnt connector behind the ash tray.

[forbey]

Thanks, all!

I plan on continuing the search. With this vehicle having over 270,000 miles and running on vegetable oil, I don't want to have to replace it. Then again, if I wait another 3 months, I'll need the heat! :)

[chris_maxwell]

I had similar issue but after replacing the module my temp adjusted correctly.

I had an intermittent issue that if the AC ran for a long period of time it would stop blowing. Ended up being a bad connector (melted) going to the blower motor; snipped out the connector and made my own, it's worked great ever since.