Electronic Climate Control

[pitzel]

Ok, here are the symptoms, 1992 Oldsmobile Cutlass Supreme with Electronic Climate Control:

 

1) On a hot day, sometimes I get air conditioning (ie: air pumped into the cabin thats cooler than outside air), and sometimes I get warm to hot air instead.

 

2) On a very cold day, I don't get fully warm air, but rather, I only get lukewarm air.

 

3) I do get, what I believe, to be, proper switchover between the upper and lower vents. A few years ago I fixed a vacuum leak to facilitate this.

 

 

What I've done:

 

a) Replaced the actuator underneath the dash that controls the airbox;

 

and

 

Replaced the electronic climate control 'head unit'.

 

 

I am at wit's end as to what to try next, and I do not have very good systems-level knowledge of the overall ECC system.

 

If I was low or deficient of R-12 in my system, I wouldn't be getting any cold air whatsoever, correct?

 

Anyone have any ideas on what my next step should be? Anyone have any schematics, or block-diagrams of the overall system?

[CuttySup]

My '97 Cutlass Supreme w/ electonic controls had the same problem, but I took more of a hillbilly approach:

 

For the air conditioning to work, I pressed the button and then opened the hood and pressed the wiring harness where it plugs into the condenser to get the clutch to engage and PRESTO! Ice cold air!

 

For the heater to work, I pressed the button and then floored it and PRESTO! Nice warm air!

[rockfangd]

lol on that l;ast one. have you researched the ambient temp sensor.. I believe there is one under the glove compartment

[rockfangd]

i will be honest i do not know a whole lot about ECC but i wish i had it, too aggrivating of a job for me though

[pitzel]

lol on that l;ast one. have you researched the ambient temp sensor.. I believe there is one under the glove compartment

 

Yeah I know where is it.

 

You wouldn't happen to know the resistance I should expect on that sensor, as a function of temperature?

[CuttySup]

lol on that l;ast one. have you researched the ambient temp sensor.. I believe there is one under the glove compartment

I don't think that's gonna help any. You can turn it manually all the way to 60 and still get warm air.

[kuwaitliberation]

Most people don't think to look at this, but the ECC has trouble codes of it's own. When you turn the A/C on look for a flashing C or F during the first two minutes. There are a ton of troubleshooting procedures in the service manual. I was just going through it to see if I could just put something up, but dang! It's like 20 pages of stuff just on the ECC systems.

 

Well, if you have a flash code, put it up.

[pitzel]

No flash code, but when I cycle through from the top temperature, to the lowest temperature, I don't see any drop in RPMs on the tach at idle.

 

Do these compressors have clutches, and if so, whats the procedure to test? Also, if you have any information on how I can pull codes from the ECC, please post, and I will go pull some if they are there.

 

Thank you;

[Crazy K]

I open the hood to see if the clutch is engaged. sounds like an intermittant issue, possibly due to a worn relay or a low charge... sometimes it works, sometimes not.

 

 

as for cool heat... is the car fully hot?

[pitzel]

Yeah I can make the compressor turn on if I hot-wire the relay under the hood.

 

I hotwired it, ran it for 10 minutes, still only hot air in the cabin. I also swapped the (known-to-be-working) fan relay with the A/C relay, and nothing changed.

 

With respect to the A/C charge....its 15 years old and the unit has never been recharged.

 

Sometimes it works perfectly fine, and sometimes not (although more often than not, it doesn't). That is whats really bothering me about this. And I don't have much expertise in diagnosing it, and I dread turning someone loose at $80/hour on it, if they don't have experience with the particular implemtnation.

 

 

[pitzel]

as for cool heat... is the car fully hot?

 

The interior never does warm up completely like it used to, in the -20 to -30C cold. And of course, this A/C problem.

 

I'm not sure how things work, but as far as I know, there are two 'doors' in the system. One controls the mixture of recirculated air to outside air. The other controls whether or not air goes over the A/C coils (evaporator), or the hot water coils (heater core).

 

I've replaced and verified the operation of the actuator that controls the mixture of recirc to outside air. But I'm not sure of the 'other' actuator, and whats involved there.

 

 

[pitzel]

Okay, I am convinced that something is wrong with the damper door that controls the flow of air between the heater coils, and the evaporator.

 

Does *anyone* have access to the manual between 1988 and 1993 on the Cutlass Supreme that describes the operation of this system?

 

Does the manual contain useful information on opening up the airbox so that I can clean the dirt and grime out, and potentially replace the actuator?

 

Or is this futile? Surely someone has managed to replace the heater core in these cars using the same instructions..

[ron350]

 

In your first post it says you replaced the actuator.

 

What was the part # of that actuator and did you use new or used?

 

 

 

[pitzel]

 

In your first post it says you replaced the actuator.

 

What was the part # of that actuator and did you use new or used?

 

Don't have the part number, I pulled it from a wreck. It was the actuator on the door that controls the mixture between outside air and recirculated air.

 

The actuator that I am concerned with now is the one that controls the mixture between air conditioning air (ie: air through the evaporator), and air through the heater core.

 

I assume they are different actuators, but I can only find one part number.

[ron350]

Hate to post a link to another forum but here goes.

 

http://www.regalgs.org/forum/viewtopic.php?t=30675&highlight=actuator

 

As far as I can tell 96 and older w-bodys use an electric actuator with #16124932 on it.

Most used ones have a broken or cracked large white plastic gear inside. GM made some with a dark blue gear and I have not seen one of these cracked yet.

 

If you have dual climate control you will have two of these electric actuators.

 

Edit:Here is a picture showing the cracked plastic gear in the actuator motor.

 

 

 

[jdeday]

Hate to post a link to another forum but here goes.

 

http://www.regalgs.org/forum/viewtopic.php?t=30675&highlight=actuator

 

As far as I can tell 96 and older w-bodys use an electric actuator with #16124932 on it.

Most used ones have a broken or cracked large white plastic gear inside. GM made some with a dark blue gear and I have not seen one of these cracked yet.

 

If you have dual climate control you will have two of these electric actuators.

 

 

Thanks Ron.

 

I looked over the thread but it is referring to dual climate control. I don't have dual does this make a difference?

 

Jeff