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Can't change heat?

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Old Mar 30, 2005 | 06:39 PM
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Default Can't change heat?

On my '79, the lever that changes the temperature of the air coming into the car (ie: the heater) won't budge from the hottest position.

Anyone ever had this happen? Any easy fix, or am I taking the whole thing apart? Squirt some WD-40 and hope for the best???

I await the reply of the many knowledgable people here.

Oh, and the car doesn't have AC, if that makes a difference.
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Old Mar 30, 2005 | 08:59 PM
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Anything involving the dash & center console will probably turn into a more time consuming job than you expect. I ~think~ thats a cable connection to the vent. I don't think I'd shoot wd40 in there without knowing what else you are soaking.
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Old Mar 30, 2005 | 09:38 PM
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Yeah, it doesn't seem like a WD-40 thing to me. The funny thing is everything worked fine before I put it away for the winter.

Anyone else with any ideas? I REALLY don't want to start taking apart the center console...it looks like it's never been taken apart, and I'm not sure I want to be the first.
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Old Mar 30, 2005 | 10:51 PM
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Originally Posted by bkerlee
On my '79, the lever that changes the temperature of the air coming into the car (ie: the heater) won't budge from the hottest position.

Anyone ever had this happen? Any easy fix, or am I taking the whole thing apart? Squirt some WD-40 and hope for the best???

I await the reply of the many knowledgable people here.

Oh, and the car doesn't have AC, if that makes a difference.
Think this : Vacuum control.Just look at your heater contol valve,then trace connections back to your control panel. At least I think that may be the issue.
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Old Mar 30, 2005 | 10:58 PM
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I know they use vacuum to change the control from A/C to Vent to Heater to Defrost.
I don't know about the C3, but on other Chevy's the control lever that controls cold to hot uses a solid steel cable wound in a steel cover. Some times those the inner cable and the outer cover will rust together. You can try to remove the cable from each end and work it free if it is a steel cable. Or, something is blocking the mixer door from moving freely. Sometimes mice get up in the car and love to move all the insulation into the ducts to make a nice home.

If the temp mixer is also a vacuum control then I would guess just the lever is stuck in the control.
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Old Mar 30, 2005 | 11:02 PM
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Originally Posted by bkerlee
Yeah, it doesn't seem like a WD-40 thing to me. The funny thing is everything worked fine before I put it away for the winter.

Anyone else with any ideas? I REALLY don't want to start taking apart the center console...it looks like it's never been taken apart, and I'm not sure I want to be the first.
Be careful,as these controls are Vacuum actuated.I have A/C,so mine is more complicated.Trace your tiny vacuum line back through your fire wall from the inline heater control valve first. Mine got brittle and parted,and I got heat in the car without touching the control lever.You may have to get into the control panel to see what is binding,also. There was a good schematic posted here a month ago showing the entire system,but maybe someone has better info.
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Old Mar 31, 2005 | 12:54 AM
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if it doesnt wanna move, dont force it! unless of course you want to pay $160 for a new one with Steel handles. i learned the hard way and now i will enjoy spending the 160 on such a small hunk -o- junk
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Old Mar 31, 2005 | 07:31 AM
  #8  
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Had the same problem in my 75. The temp control is a steel cable wrapped in a wound steel jacket, as indicated. In my case it turned out I had bent the cable a little too hard when I installed the aftermarket head unit. I removed the side panel from the console and was able to correct the problem pretty easily. Good luck.
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Old Mar 31, 2005 | 07:59 AM
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From: Reynoldsburg Ohio
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Any tricks to removing the panel? Are there any more screws than the 4 holding the black plastic panel (with the shifter diagram, and the controls for the heater)? Does the panel just pop off? And how can I go in from the side...?
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