I own a 97 Deville which I love but a few days ago my heat just stopped working... I can't even get A/C... At first I would hear what I guess is the blower and I would get a little bit of heat from the from on the drivers side floor but now I don't hear anything or feel anything but I would get this slight burning smell which makes me gag... I'm so upset. I really hope this is a easy fix because my extended warranty just ran out back in January. Any help is appreciated guys

First we have to see exactly what went wrong, it has to be narrowed down, the following is just a starting point,

Functional Check without D55
The following operational test sequence aids in determining whether the following HVAC system is functioning properly:

Electrical
Air distribution
Vacuum
Refrigeration
Ensure that the ambient air temperature is above 5°C (41°F). Ensure that the engine is warmed to the normal operating temperature.

Function Test for System Action
Normal Result

Start the engine.
The engine warms in order to perform the test.

Press the OFF button.
With the blower OFF, the display shows the following information:
The set temperature
OFF
The outside temperature

Press the AUTO button.
The system turns ON.
The display shows the AUTO fan and AUTO mode.

Set the temperature at 15°C (60°F).
The blower is at high speed.
Cold air flows from the A/C outlets.

Press the ECON button.
The RECIRC LED turns OFF.
ECON is displayed.

Press the RECIRC button.
The RECIRC LED is ON.
The blower noise slightly increases.

Press the AUTO button.
AUTO is displayed.

Set the temperature to 32°C (90°F).
Hot air flows from the heater outlets.
The RECIRC LED is OFF.

Press the DEFOG button (if equipped).
Air flows from the heater outlets.
The RECIRC LED is OFF.

Press the RECIRC button.
The RECIRC LED is ON.
The blower noise increases slightly.

Press the DEFROST button.
Air flows from the windshield outlets.
The RECIRC LED is OFF.

Press the FAN down button 2 times.
With the blower at low speed, LO is displayed.

Set the temperature to 24°C (75°F).
Press the AUTO button.
AUTO is displayed.

Press the PASS TEMP on the jet to MAX WARM.
The air from the right side A/C outlets should be warmer than the driver side outlets.

Most likely the blower went south. They are known to do that and have been redsigned. It's pretty easy.... the second time (don't ask). This link should let you know what you are in for which in itself will make it a little easier.
http://www.cadillacforums.com/forums/cadillac-tech-tips/46611-97-deville-blower-motor.html?highlight=blower+motor

Thanks for the info... Your knowledge is always apprecatied.

I did a quick run through of the test and I'm not getting anything. No air flow from the upper or the lower vents with all fan speeds tried. But I can here the something in the engine comparment but I really doubt it is the blower because I should have gotten some type of air flow but then again I could be wrong. I forgot to mention that I just replaced my spark plugs and I was reading some past treads that said that the wiring for the blower could be to close but thats not the case. With everything said I belive its the blower, I like to think I'm mechanically incline but I think this might be to complicated to to myself... how much do you think this might run me???

If you are mechanicaly inclined, you can do it. If you read my post, most of it is moving a few things out of the way. The hardest part is rocking the engine, but in hindsite (knowing what I know now) it wasn't all that hard. I think I paid $225 for the blower from gmpartsdirect. I think the dealer quoted me $386 if I remember correctly (for the part). I don't know what they get for labor on that. I would guess at least 2 hrs ($200 or so).

Young DeVille,

Spend the $40 for the GM engine moving tool. It makes the job super-easy.

1) Disconnect neg battery terminal. Remove the larger dog-bone(on the driver's side near the front of the engine compartment) and replace with the GM Thexton engine moving tool.

2) Remove smaller dog-bone on the passenger side near the front of the engine compartment.

3) SLOWLY tighthen the engine moving tool making sure you don't sever any hoses parts as the engine moves closer to the front of the compartment. After you've got a couple inches of clearance near the blower motor, disconnect the blower motor electrical connector and remove the 5 bolts.

4) Remove the old burned up blower motor(it may need to come out in a couple pieces if the clearance is not enough). Replace with the new blower motor and secure it with the 3 screw/bolts(I don't remember which).

5) SLOWLY reverse the process using the engine moving tool so the engine moves back into place.

6) Fire up the car and enjoy your heat and A/C.

I wrote this from memory and it's been a while since I've done it, but you won't be disappointed if you buy that engine moving tool. The whole job only took me about 90 minutes. If I missed a step, someone please reply.

I bought my new blower motor off eBay from a GM dealer for $190 shipped.

Thanks for all the info guys... I found the engine moving tool eBay for under $40 shipped... I narrowed down the problem and its really appers to be the blower I can hear the vent open but theres no air flow from any of the vents. I've been looking on eBay and I belive I've came across a good deal on a blower $190 Brand New shipped... I'll keep you guys updated on my progess on the appears the be my most extensive repair that I've ever done myself anyway. Wish me luck:bouncy: .

My recently purchased '90 deVille had similar heater problems, notably very weak to no heat-air flow out front vents but slightly stronger defrost action on windows. Simultaneously, my parking brake would not snap up the last fraction of an inch so the dash light stayed on.

I replaced the dead blower motor with one from a junkyard ($36) and that helped, but along the way broke (or found) some broke stiff plastic vacuum hoses (they get brittle) and well, to cut this short, after replacing two hoses everything worked like new. Got strong flow of cold/hot/air out of front vents, and the parking brake became good to go.

I must therefore conclude those vacuum hoses were also part of the problem. Hope this helps.

The air distribution doors are definately vacuum controled. That parking brake release on earlier models was also vacuum controled and was on the same vacuum circuit.

Alright guys... I ordered the the blower off GM parts and the spark plug wire kit because these a slight misfire and I said I kill two birds with one stone. I'll keep you guys posted on my progress and thanks for all the info.