Question about 1991 Cadillac DeVille

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The service air conditioner light on our 1991 Cadillac sedan deville 4.9 comes on when I turn the air conditioner on. The electronic climate control will not let me turn on the heat or the ac. It just defaults to economy. The ac at this point no longer blows cold air. I push the off button and eventually the light goes out. Do you have any thoughts on what may be causing this? Thank you for your help in advance. Sincerely, Chris

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Prob a low charge easy to do get R134a from parts store with hose start with about half a can and check it make sure ac is on max when you charge it light should go off

Posted on Oct 02, 2010


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Cadillac deville 89 fuel data center and climate control arent working.

Hello Belinda Reid,

Nice car...
(sorry... I'm sure you are not in the mood right now)...

There are CADILLAC Clubs across this country
(lovers, admirers, professionals & amateurs)...

I recommend for future issues you seriously consider
looking into joining... The wealth of information is
really quite EXCELLENT... or buying your own set of

For these issues... (I doubt they are related)
would be the best approach...

repair manuals ... but FREE circuit drawings & your 22 TECHNICAL Service Bulletins (TSBs) can be found
on BBB Industries website
(registration is required... these are real documents)
BBB Industries Premium Alternators Starters Power Steering Products

In the 1989 Deville (an issue shared issue w/Eldorado) ...
I did find a TSB on "BLANK DISPLAY" ... Ironically the
TSB page was also blank (GM humor ..
(I presume)).

The FUEL GAGE seems to be a popular part...
(typically means "unreliable: great point to START").

On eBay (refurbished (1 year warranty)

Rockauto (out of stock (I rest my case)),1989,deville,4.5l+273cid+v8,1025693,fuel+&+air,fuel+display+control+module,10492

Extra information

Also see HVAC Controls, Motors & relays
(another OUT of STOCK: popular part)...,1989,deville,4.5l+273cid+v8,1025693,heat+&+air+conditioning,programmer,19408


ENTIRE control panels are available on eBay(some good... some NOT-SO-MUCH (but you are protected (sorta)).

Dress warm... happy hunting
On the HVAC if the controls seem to be working... another
popular part are in the ACTUATOR DOOR sections of your parts catalogs...

Look through the eBay parts for ideas...
0results for cadillac 1989 deville hvac vac control
AND don't overlook the CONTROL RELAYS that ABOUND in
your vehicle... Buy a few spares BEFORE they become rare.

Hope this helps.

Carnac the Magnificent

Oct 22, 2017 | Cadillac Cars & Trucks

1 Answer

How do i turn on my climate control

Climate control is turned on by pressing the 'auto/econ' button.
There will be a temperature control for it that lights up on the right hand side of console display. One can also control the fan speed there or leave it on 'auto'

Sep 01, 2010 | 1989 Cadillac Sedan DeVille

1 Answer

I have a 1996 Cadillac Sedan DeVille. This spring...

If the a/c does not engage as a result of the electronic control system in your 1996 Cadillac, the climate control system may need to be replaced.

However, if the problem is being caused by low charge of R134a in the system, have the system charged before changing that electronic part.

I have never seen a Cadillac Climate Control System do this, which leads me to believe that it may be more electronic than refrigerant pressure related.

If the refrigerant pressure was low in the system, the climate control system should still stay on 'auto' mode, I think, and simply blow warm air.

May 19, 2010 | 1996 Cadillac DeVille

1 Answer

What are error codes E98 and F47 for 1992 Cadillac Deville

The E98 is P/N to D/R In ISC (Idel Speed Control) Range problem. This code will not trigger a service light.
The F47 is Refrigerent System Problem. This code turns on the Service Air Cond light, and switched the Climate Control from Auto to Economy.

Mar 01, 2010 | 1992 Cadillac DeVille

1 Answer

When i turn on the cliamte control the 'service air conditioner' light comes on

the pressure switch is getting a low reading. change the seals on the compressor,and get it re charged.

Jan 10, 2010 | 1991 Cadillac DeVille

1 Answer

Replacing a 1991 cadillac sedan deville air compressor

The lines should be differant sizes.. Did you check it? Ther should be a diagram on the cover over your radiator showing you the set up.. Hope this helps..

Aug 26, 2009 | 1991 Cadillac DeVille

1 Answer

88 cadillac deville, ac blower fan wont shut off, even when car is turned off and key removed. I tried disconnecting the battery to reset the system but it still runs when battery reconnected. Also, car...

Most common cause of this is the blower fan (proper name for the fan you refer to) continuing to run is a shorted out Electronic Climate Control Module. This solid state device replaces the older style fan speed resistor block (at about 4 times the price) This unit is found on the top of the HVAC box under the hood. (HVAC means heating, ventilation and air conditioning) The HVAC box is found on the passenger side of the firewall. Look behind the A/C's accumulator. It will have an electrical wiring plug on top of it. It will be fastened to the HVAC box with a few 7mm hex head screws. Very easy to change.
FYI, do yourself a favor and replace the blower fan motor at the same time. The Electronic Climate Control Module usually fails because the motor is drawing to many amps of current. This is because it's bushings are worn out or the brushes are worn out.
This is very common on Cadillacs and Buicks.
PS Not sure why car won't start. Either you drained the battery or blew a fuse which controls starting the engine. Need more info regarding the "no start" condition.

Jun 14, 2009 | 1988 Cadillac Sedan DeVille

1 Answer

Dont know how to turn my air conditioner on in my.I

Your car has climate control. If the Ac isn't turning on at all, it's most likely low on refrigerant (R-134A). Below is a link on how to check/fill AC systems with refrigerant. Otherwise, the car should be serviced by a qualified AC shop. Hope this answers your question. All the best!

Jun 03, 2009 | 1995 Cadillac DeVille

1 Answer

Fuel Data Center and Electronic Climate Control not funtioning

This is defenetly the BCM, I had a 1990 with all of the same problems. Buy a rebuilt and install it behind the clove box. Remember that you must install you memory prom into the new unit as they don't come with any in them (it is what is memorizing your miles driven.) You will get off pretty easy on this one as they are available and not too expensive.

Jan 13, 2009 | 1989 Cadillac Sedan DeVille

1 Answer

Electrical Problem with 90' Cadillac Sedan Deville

the climate control is intergrated through the pcm and ecm i would advise you to take the vehicle to the service shop they have a diagnostic scanner that will access the ecm and either clear a code that prevents the climate control from working or find a more severe problem that requires you to replace the hole unit. please rate this solution. thank you and good luck.

Aug 29, 2008 | 1990 Cadillac Deville

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