Heater Control Issue

[incubus2432]

So this is the control unit for my a/c and heating......

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On the "DEF" setting plenty of heat comes out of the windshield vents and some at the floor. On the "A/C" setting air primarily comes out of the dash vents (but it isn't nearly as warm even with the temp setting fully on "Hot"). The issue is when I try to set to "HEATER" nothing much comes out of any vent set and the slider falls left or right from the center (there is no detent and it's almost like it's being pulled to either side).

Pull the control unit and lube, live cables, live with it? Thoughts?

 

[Jims86]

So this is the control unit for my a/c and heating......

You must be registered for see images attach

On the "DEF" setting plenty of heat comes out of the windshield vents and some at the floor. On the "A/C" setting air primarily comes out of the dash vents (but it isn't nearly as warm even with the temp setting fully on "Hot". The issue is when I try to set to "HEATER" nothing much comes out of any vent set and the slider falls left or right from the center (there is no detent and it's almost like it's being pulled to either side).

Pull the control unit and lube, live cables, live with it? Thoughts?

There are also vacuum operated servo's under there...3 I think. First thing, is to make sure the vac line going to manifold vacuum on the engine is in good shape. Then check the vac switch valve on the back of the control unit.

 

[incubus2432]

Excellent info......thank ya' much!

 

[89Suburban]

Here is pics of the housing and doors and stuff, these are from '89.

http://www.gmsquarebody.com/forum/showthread.php?t=4809

 

[CorvairGeek]

This is a control head for one of the aftermarket A/C systems, so it will be different than most of us have seen. The aftermarket part of the system is directing the air flow from the OEM heater assembly. Checking for a loss of vacuum would be a good start if it isn't a completely mechanical system.

 

[RetroC10Sport]

This is a control head for one of the aftermarket A/C systems, so it will be different than most of us have seen. The aftermarket part of the system is directing the air flow from the OEM heater assembly. Checking for a loss of vacuum would be a good start if it isn't a completely mechanical system.

Yeah, I was gonna say...Never seen one of those before.

 

[bucket]

Yeah, I was gonna say...Never seen one of those before.

X2.

I'd like to see what's on the backside, very curious how it's setup.

 

[incubus2432]

Interesting info. Thanks and I'll be sure to post plenty of pics when I tear into it. I have to give the truck an oil change and tune-up first so it may not be for a few days when I get some time. it's not a huge deal since it still gets toast in the cab but having it functioning properly would be nice.

 

[89Suburban]

No ****?

 

[incubus2432]

So just to give an update......

I drove the truck the other day when it was about 24 degrees out in the morning and even with it blowing just out of the defroster vents the truck warmed up fine inside. For right now I probably won't mess with it much for now. I have to finish cleaning off the glue from where I pulled the moldings and touch up a few paint issues plus replace the carb so this project is a little lower on the list.

I will certainly remember to post a write up when I finally get around to this mini-project. Thanks again for the input.