No cold air from vents on 1981 Seville (Who is the electronic guru for the AC)

[Barry M Wheeler #2189]

I had the AC recharged on the 1981 Seville last week and my local guy said, "Well, uh, the last few times the car has been in here, the only air came from around my feet. Duh, I thought you knew that it's "always" been that way. It's gonna' be way expensive and we don't have parts and well, you might take it to a Caddie dealer."

(I had let my son-in-law drive it to work and back (about a mile) last winter as he sent his spare car to my granddaughter in NJ.)

I should have our expert's name set aside somewhere but I don't. HELP! Offering these jerks a Shop Manual doesn't seem to help. Maybe they can't read...

I know that the vacuum for the doors isn't working, but would appreciate some advice. (I do have the manual.)

["Cadillac Kid" Greg Surfas 15364]

Barry,
First thing I would want to know is if , even though the air is only being delivered through the lower vents, does the temperature change from cold to hot while slowly (with the car warmed up) rotating the temperature dial from full AC to Maximum heating?
If so then I would look for either a leaking (or disconnected) vacuum line or a bad mode door actuator.
Greg Surfas

[Barry M Wheeler #2189]

Thank you Greg. This car doesn't have the dial, but buttons, so it may have been one of the very early electronic ones. I haven't had time to mess with it much as we had ten windows replaced in our home last week and I haven't recovered completely from that. I did go through the "ladder" causes and effects in the Shop Manual, so I know a little more than I did.

The trouble might be in the programmer, but as I said, I haven't had the time to delve into it yet. Thanks for the suggestions. The air coming from the floor is "cool", not cold, so I may have trouble finding any graduation of heat to cool.

["Cadillac Kid" Greg Surfas 15364]

Barry,
The trouble shooting matrix in the 81 FSM is good.  You need to check out each individual ATC system (refrigeration, heating, fan motor, air distribution and controls) to be sure it is functioning.  OR, you can just go ahead and spend money and throw parts at it until something works.  Pardon the sarcasm. Its hot and humid here and I just finished switching my '75 back to R-12 from R-414b. I''m tired.
Seriously, check and see if the numbers on your control head as you try and toggle it between full heating and full cooling (slowly) and see if there is ANY difference in outlet temperature while you are doing so.
Greg Surfas

[Barry M Wheeler #2189]

Yuch! Had the '91 recharged about ten days ago and they said to bring it back about this time to check for leaks. (Not needed as the dash reads, Compressor turned off due to low refrigerant...) So at least they'll do something with this car.

[Barry M Wheeler #2189]

The 1991 Seville was done quickly this morning. It turned out that the low side service port was leaking. A new valve was put on under warranty so we are now cool at N/C to me. Now all I need do is figure out what's wrong with the '81.

[79 Eldorado]

Barry,
In your orig post you mentioned the vacuum isn't working. I have more experience on the semi-automatics but at least on those of the same vintage "everything" is controlled by vacuum. If you temp door (aka blend door) is in a mode for heat only you will never get cold air.

One other thing, again it may be unique to semi-automatic, is a vacuum check valve. I had one go bad in my 1984 Toronado and I had only hot air despite the AC loop functioning perfectly. A friend with a 1983 Toronad had exactly the same issue; heat only despite cold selected. I changed that single part in both cars and the system was perfect again.

Take a look in you FSM and you should find a vacuum diagram. On the semi-auto systems there is essentially a vacuum distribution junction. You can find the one for the blend door and you can apply vacuum with a mightyvac and listen for the door as it moves full to one side or the other.

One other thing I've had more than one E-Body (cousin) with the main vacuum line deteriorated in the area where it goes into the firewall (just before thankfully). Look for a severed vacuum line near the firewall-right fender area. If it's broken you can cut out the bad portion and use a slightly larger tube to connect the 2 halves.

Good luck,
Scott