climate control, "95 SC

Sharon Silver

Registered User
If I start the car with the climate control in any given position and leave it, it works fine. If I start it in an a/c position and move it (max a/c to a/c or to defrost) or move the temp setting away from 60, the thing is cold for a varying time then switches to maxium heat. Once in this heat mode, it will not switch back to cool no matter what the controls are moved to. If set the controls to 60, shut off the car, set the control to max a/c, and only max a/c, then restart the car, it will usually return to cooling. Then I can shut off the car set the control to a/c, restart, and it will stay cool. The "usually" occured the other day: after the max a/c restart, the heat came on again. I shut off the climate control and a few moments later the 'check engine' light came on. The car was running fine and the gauges were ok. So, I shut off the raido to listen and the check engine light went out. On a hunch, I flicked on the a/c and it was cold. I turned on the radio and it worked, no engine light. Any guesses? ( polotergeist is my theory :eek: )
 
I'm assuming that your EATC is similar to the one in the earlier models with the exception of the controls which are rotary instead of pushbuttons.
In heating mode, can you control the temperature and can you change the airflow by switching from VENT to PANEL/FLOOR to FLOOR to FLOOR/DEFROST to DEFROST?
Can you control the blower speed?
Do you hear a momentary hiss from the control unit in the dash when you rotate the function switch between positions.
Do you get any error messages in the digital display (E1 to E9 or P2 to P9)?
I'm trying to find out if the A/C clutch is malfunctioning, if there is a vacuum supply problem causing the system to switch from A/C to heating or move the blend door to the wrong position, or if the climate control unit is bad.
 
more info

The a/c clutch is fine. Everything on the heat side works fine provided that it has not already gone into the super heat mode by it's self. If I switch from a/c to defrost, it works for a minute or two and then goes to full heat, even with the thing set on 60. It will not come off full heat no matter where the switch is unless the car is shut off. Undoubtedly the problem concerns the vaccumm, I'm just unsure if it is a controler problem, sticking accuator, or something else. I get no error codes and the blower speed works as advertised.
 
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It's possible that one of the three sensors is bad, but then that would probably trigger an error code.
Here's the procedure for checking for error codes on the earlier models. You probably can use it. In steps 2 and 3 you will have to rotate the controls.

To identify existing as well as intermittent errors, start self-test by performing the following steps:

1. Turn ignition switch to ON position.

2. Depress FLOOR button on control assembly.

3. Slide blower lever to high.

4. Push both COOL and WARM buttons simultaneously for three seconds until -- appears in the control assembly window.

5. After about 20 seconds, the -- symbol will be replaced by a code. Refer to the «Error Code Key» to identify the error.

6. If 75°F or 24°C appears, power to the vehicle has been interrupted. Repeat Steps 1 through 4 above.

7. To exit the diagnostics mode at any time, turn ignition switch to OFF position or depress the OFF button on the control assembly. When the control assembly is turned back on, the temperature door will self-calibrate for 20 seconds.
 
If you cannot shut off power to the EATC using the rotary switch, then I would say that the control unit is defective.
 
J.D. said:
If you cannot shut off power to the EATC using the rotary switch, then I would say that the control unit is defective.
I have moved the switch to the "O F F" position, but nothing happens, in fact, everything quits working.
 
I know this may sound wierd, but it is worth a look, trust me. Check the A/C fuse connection in your under dash fuse box. I had very similar problems to yours and they drove me nuts until I figured out that I had several loose connections in the fuse box. These are the connectors that the fuse snaps into and makes the actual contact with the board underneath.

If you can wiggle the fuse and the system goes on and off, then your problem may very well be nothing more then an intermittent contact through the fuses.

It should take all of about 2 minutes to rule this out. Pop the fuse cover, and if I remember correctly, the fuses you are looking for will be the first and second ones on the front left side.

Hope it's as simple as this.

Ira
 
exercism!

While I do have some issues with Ford wiring and the fuse box an my '92, I think I've fixed my '95's problem and you won't belive it: on top of the fan discharge bucket is a hole with a rubber manafold bolted onto it. From the side of the manifold, there is a "hose" that goes to a box above the fan motor, from which a white spiral hose runs up into the dash and exits to the right of the raido, from what appears to be an audio vent above a "Premium sound" sign. Anyway, back at the manifold, the other opening was apparently blocked with a white nylon plug (which would increase the pressure to the white hose.) The white plug broke in half, allowing the pressure to vent into the dash area. I silicon glued a liner from the lid of a pill bottle to the open end of the manifold and haven't had a problem with the a/c all day.
 
The in-car temperature sensor is mounted behind the vent next to the radio. This is one of the three sensors mentioned in post #4. The white spiral hose draws air over the sensor in order for it to correctly measure the air temperature inside the car. If the airflow inside the white hose is in the wrong direction, then the sensor will read the temperature at the blower and A/C evaporator, which is very cold air since the temperature control was set to 60 degrees F. The climate control will try to compensate and raise the air temperature by routing all the air that flows from the blower (and then through the A/C evaporator) through the heater core instead of bypassing the heater core either completely when A/C is chosen or partially when defrost is chosen. There was no error code since the sensor was functioning correctly. That's my theory.
 
Once I figured out where the white hose was dumping out at, I got the same picture. It's been a couple of days now and no problems. It's amazing how important super glue and silicon have become in a modern girl's life.
 
Try your CCRM (its up by the headlight) when i was having problems with my a/c that was what was wrong with mine, it basically controls everything and they way it sounds is that its just starting to go out. all the wires go into it and one wire comes out of it.
 
sweatin' in San Antonio

94SCBird said:
Try your CCRM (its up by the headlight) when i was having problems with my a/c that was what was wrong with mine, it basically controls everything and they way it sounds is that its just starting to go out. all the wires go into it and one wire comes out of it.
My "fix" didn't. Just what is a CCRM anyway? Can you give me a better discription and location? At least which headlight. Thanks.
 
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