A/C issue - 82 Cordoba

Yellowdart69

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I haven't checked this year, but last summer, the A/C, would only blow Cold, if fan speed was on Max, setting. All other settings, it blew hot air. Is there a simple fix? Thank you.
 

GregG48213

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simple fix?
I had a similar problem on my 1988 Diplomat. The servo-controlled blend door was stuck on full heat. The fix was not simple. It involved taking the dashboard apart (riveted panels) to get to the heater box. I removed the servo and gradually freed the stuck door with vice grips attached to the hinge that went into the servo. This advice may only apply if you have Semiautomatic AC.
 

Yellowdart69

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I had a similar problem on my 1988 Diplomat. The servo-controlled blend door was stuck on full heat. The fix was not simple. It involved taking the dashboard apart (riveted panels) to get to the heater box. I removed the servo and gradually freed the stuck door with vice grips attached to the hinge that went into the servo. This advice may only apply if you have Semiautomatic AC.
I should have mentioned - yes, it is the semi automatic.. But why does the AC work, on highest fan speed, but not other speeds?
 

GregG48213

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why does the AC work
The AC does work in the other positions (Norm & Bi-Level), but it can't cool the car because the blend door is stuck on full heat (or the servomotor is broken). Max AC closes off outside air. The speed of the blower is controlled only by the fan switch.
 

Aspen500

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No idea what fan speed would have to do with the A/C not working. However, if the blend door isn't working you'll get some heat, or a lot of heat unless you select MAX A/C. Along with the recirc door moving to inside air, it also shuts the coolant flow off to the heater core using a vacuum operated valve in the heater hoses, under the hood.

Sorry, I'm kind of confused as to what exactly you are saying and describing.
 

BudW

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There are two different issues here at play.
The first one is the difference between “A/C” and “Max A/C” buttons. The difference there is the A/C control head turns off the hot water valve so the heater is out of the loop/out of play in this case when “Max A/C” is turned on.
AC head SATC.jpg


If A/C only blows cold in the “Max A/C position, then your blend air door (or in case of SATC, the servo motor) is not working correctly, stuck or disconnected.


The next issue is blower speed(s) – blue circle (below).
91 PU Control Hd q.jpg


If blower will only blow when switch is full up – then the blower switch or blower resistor is bad, or wiring connector to the resistor is disconnected.
Blower Resistor 20470.png

The blower resistor

The blower switch has two small screws that hold it on (one top and other bottom). The switches come with a chrome lever or a black plastic one. It will work with either handle – but it looks goofy when you do that.
Most blower switches can be replaced after the A/C control head is unscrewed from dash and pulled out a short distance.
Blower Switch HS-203.png


The blower switch and blower resistor are both available aftermarket (new).

I don't like having the A/C fight the heater system (the heater will always win) – but on the same note, after temperature has stabilized, having the heater on does make it more comfortable.


For those who do not know, what Chrysler recommends for best cool-down performance when getting into a hot cat, is to first turn “A/C” on (not Max A/C) and crack a window (or two) down a bit (a minute or two). That will push the really hot air out. Then push “Max A/C” - which turns off the heater and turns on recirculate inside air. Once car gets “cold”, then turn back to “A/C” and adjust heater to get a desired temperature.

The SATC servo went bad on my '86 Fifth Ave, so I got parts from a non-SATC system and converted it over, then tossed out all of the extra electrical parts. A/C now works fine - other than I have an expansion valve gasket leak that needs replaced (slow leak).
BudW
 

Mikes5thAve

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To me it sounded like the fan works on all speeds but cold air only comes out when it's on high.

No idea on the AC thing unless what you are feeling as cold air is more related to feeling the air from the fan itself. Like others have said fan speed only controls fan, nothing else.
Does the controls work for all other heater settings? Air re-directs itself to the different vents for heat, ac, defrost? If you move the temperature lever can you feel the temperature coming out change?
 

Justwondering

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BudW --
On behalf of everyone, thank you for taking time to provide such helpful and just the right amount of detailed explanation--with pictures.
I know it takes time, but I very much appreciate your efforts.

JW
 

Duke5A

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So you do have the servo controlled blend door? The one on mine stopped working two years ago. When you run the temp slider side to side you should hear it actuate. That servo is a noisy little critter. What happened is the plug that connects to the servo assembly lost all tension and the connection wasn't good. You can indeed reach it without taking the entire dash apart - just the glove box and lower panel.

Once I had it out I took the assembly apart, removed the board, scuffed the contacts up a bit and built it back up with solder. After that the plug fit nice and tight again.
 
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