Heater/AC on my new Eldorado

[Rick Biarritz]

As noted earlier, I purchased my new '83 Eldorado on Monday.  I drove it from NY city to VA with no real problems, but...  It rained the whole way and I kept defrosting the windshield, and I would crank up the heat to 80, 85, and even 90 degrees, but it kept blowing ice cold air.  No heat at all.  The ac obviously works fine.  Any ideas?  Is this somehow related to the 4100 overheating problems I keep reading about?  Thanks.

["Cadillac Kid" Greg Surfas 15364]

Rick,
The first thing I would check is the heater core, water lines and valves.  Are the heater hot water lines connected? Is there a shut off (manual) valve in the line that is closed?  Does the heater control valve function?
After you have checked these and if you don't find an answer, let us know.
Greg

[Brian McKee]

I just bought a 1989 Edorado Biarritz this week. I had the opposite problem.  It was heat all the time.

The air-conditioning was fully charged and the compressor was working.

It turned out to be flapper valve that opens the air-conditioning/shuts off the heat, or vice versa.  The small pin in the valve was broken.  The small pin was replaced and everything is perfect now.

This is worth checking out.....

My "new" 1989 Eldorado Biarritz only has 81,000 miles and is in excellent condition other than some cracks in the leather of the two bucket seats.  I want to get that repaired.  This is a dream car for me. I have had almost all of the Cadillac models except an Eldorado. I am so excited to get it.

[Rick Biarritz]

Do you know where this flapper valve is?
Thanks.

[Brian McKee]

We discovered the heater/AC problem when I took the car for a test drive after it was traded in. The elderly couple who had it never used the AC as they were always cold.

The dealership repaired it for me as part of the purchase agreement.  So, I didn't see the repair.

I do know that on the 1989 Eldorado, they had to take out the glove box to get to flapper valve. It was one of those times when the part to fix it was about $1.00 but they spent about a day and a half labor to get to the part to replace it.

[Otto Skorzeny]

Rick,

Have you purchased a shop manual for this car? If not, try to find one on ebay or buy a Haynes manual at Pep Boys or whatever. Better yet, get both. The Haynes manuals often have better illustrations than the factory shop manuals and the instructions are usually easier to follow.

[Rick Biarritz]

Oh yes.  The shop manual is definitely on the way.  When you are as inexperienced as I, the SM is a must.

[Otto Skorzeny]

It's a must for anybody regardless of experience. There is no way to properly work on any vehicle without a shop manual for reference - even if it's only to look up torque specs and fluid capacities.

[Glen]

It sounds like your problem is a stuck temperature door.  The door moves to allow air flow through the A/C evaporator or the heater core.  By setting the door to the correct position it mixes the air to get the temperature you need.  But if the car sits too long the door may stick. 

Glen

[Rick Biarritz]

Thanks for these tips.  I will begin checking them out. 
Rick

["Cadillac Kid" Greg Surfas 15364]

Rick,
One of the things I din not mention earlier is the possibility that because of defective control system components or due to a lack of understanding someone in the car's "past" may have circumvented the electrical and vacuum circuits of the control system and left you with cooling only.
I would first check for heater hot water flow, and then, with the shop manual and control circuit diagrams in hand ( the diagnosis section of the AC Controls is extremely helpful) verify that everything is hooked up as intended.  After, and only after that step should you spend the time to chase gremlins.
Greg