climate control problem

[Biggie]

I'm having issues with my 95 SHO climate control. For a couple months now, when I adjust the air temperature it's not regulating it properly. If I start the car and have the temperature set to around 15-20C approximately it will blow cold air, but when I set it beyond that it will only blow hot air. If I max out the temperature and then try to bring it back down to 15C, it will not adjust to a lower temperature and only blow the same hot air. Sometimes if I shut the control unit (EATC) off and let it sit for a bit, then turn it back on to a 15C it will start to blow cold air. Not all the time it will do that though.

Just looking for some recommendations and what to start with.

 

[rubydist]

when you set it to full cold and it blows hot air, is the a/c compressor running or not?

I suggest you do the eatc self test to see what that shows.

 

[Biggie]

I should've mentioned...by cold I mean just vented air since the A/C doesn't work right now...one of the lines has a leak.

Earlier this year I swapped out the blower motor control module as I found it was causing an odd ticking sound sometimes when the fan was running. I also checked over the vacuum lines and electrical connections under the glove box and they all seem to be attached.

I found a link on doing the self test and will report back.

Thanks

 

[Biggie]

I ran the self test and as soon as I press the automatic button and for it to scroll for approximately 30 seconds, it's completely blank? Is that normal? I don't see any scrolling or moving lines. Anyhow, after the test I was prompted with code 02. When I press the defrost button to clear, nothing happens. The blue button works however. During the test I do hear a vent/blend door making slight opening closing sounds. As soon as I exit the test and run the system normally it seems to make a lounder thunk sound but it was only blowing hot air.

I also came across a large size hole which i believe was made into the unit near the driver side gas pedal. Any idea why someone made this?

 

[luigisho]

Someone trying to keep their feet warm in the tundra up there?

 

[Biggie]

Ahh yes, that makes sense lol....gotta keep them tootsies warm. I covered it up now with some Gorilla tape. I have a spare parts car which I can try swapping the EATC control unit from and see what happens. Could the air temperature sensor near the header panel/condenser cause any problems? It seems to read the outside temperatures correctly though. Also, is there an cabin air temperature sensor located in the car? Just wondering if these could throw things off.... I also do have a parts car which I can try swapping these parts from to see what happens. Any suggestions?

 

[Biggie]

Just an update.

I took out an eatc (controller) from a 94 and tried that and it gave me the same result and 02 code. The actuator could be at early stages of failing, but i'm not completely sure because it's blowing both temps, just not regulating and switching the temperatures correctly. A couple online part suppliers carry an cabin air temperature sensor (pictured below) for the car, but I have no idea where it's located? If the car uses one I'd like to try that out before tackling on the big job.
A while back I took apart a dash from a 94 scrap parts car and today looked around the dash as well as the complete blend door assembly that was removed but I didn't spot it. I also find it odd that the car had a 90-92 actuator instead of the 93-95 one. I was hoping I could see what's in my 95...but there doesn't seem to be any angle to see it.

If I have to take on the task of removing the dash to change the actuator, what else should I look at replacing? I read that it's good to change the heater core. Should I change the blower motor and A/C Evap core as well? Are they known to fail?

 

[luigisho]

It has to use one to regulate cabin temps when using auto settings

 

[rubydist]

iirc, that internal temp sensor is behind the dash somewhere on the passenger side of the center. There is a small opening in the dash that allows the little hose to draw air from the cabin and pass it over that sensor. It might be easiest to search for the little flex hose behind the dash. I think its about 1" diameter - to fit on the sensor.

 

[Biggie]

Yes, it was located directly behind the SHO badge insert piece. It was dirty alright...but unfortunately not the culprit. I cleaned it and also tried using one off my parts car. Still wants to change to blowing hot air. Was well worth the shot though. Can't think of anything else other than a new blend door actuator? Any suggestions of other parts I should replace while I have it out of the car?

Thanks

 

[luigisho]

I guess you could do the heater core if the whole thing is coming out. Not fun but if it goes you have to pull the dash again...or dump the car

 

[Biggie]

That's what I was thinking as well. Just ordered up everything (BDA, heater & Evap core, blower motor) and will get to it at some point... car gets parked soon for the winter anyways. I have read a few different guides on removing the dash and there seem to be different methods....some taking longer than others. Is there a preferred one?

Thanks for your help rubydist and luigisho.

 

[rubydist]

Its been a while since I did that, but iirc you don't have to pull the dash completely out to get the hvac housing off the firewall. I think you can loosen the dash and sort of lift the passenger side up so you can get the hvac stuff out from under it. In that way, I don't think you need to disconnect all of the wiring harness. But, as I say, its been years since I did that last, so I may not recall everything correctly...