Well, this all started when I have to replace my ignition lock cylinder, when I got it back togeather, I had no brake lights, but my ac worked fine, so the next morning I went and picked up a new turn signal switch and the ac was working fine, later that afternoon after finishing with the turn signal switch replacement, the ac blower does not work, in any mode, the compressor is cycling on and off like it is suppose to, the air doors move when you change modes, just no blower function in AC or heat or econ.

I ran the overide for blower function and still no joy!

I have ran it to max AC at 60 degress and at max heat at 90 and still not blower function.

Any ideas or thoughts on what to check next would be great.

John

Did you ever find out what was wrong, mine has started doing the same thing, except it was fine when I pulled it in the garage last night and then this AM "nothing" have checked all the fuses and they seem fine. Thanks

Check that the motor is physically firm in the molding. Lift it a little with power on, and see if it starts. check the rear fan if fitted.

This motor pulls a fair current when stalled, so check to see if the wires at the plug are a little warm. Check when engine cold of course.

Thanks, but I think my problem is the blower itself and after reading another thread (no heat or air conditioning fan (http://www.cadillacforums.com/forums/showthread.php?t=34903) ) I'm about positive, it's getting juice but no go and after reading some of the other posts it sounds like a known problem, the good part is it can come out with just 3 screws, the bad part is you can't get it past the motor without a heck of a lot of hassle. I can get the blower motor itself for around $230.00 from "Advance Auto" compared to around $350.00 from Caddy not to mention what they want for labor which varied wildly anywhere from $300.00 to $600.00 from what I've been reading. It seems to be a matter of getting the engine a couple inches forward, I ve read several diff. approaches to it so I'll try myself first and see what happens.
Bob

Okay, but make sure that it's not simply stalled first. There wouldn't be any difference in the symptoms of a jammed motor or an open circuit one except for the warm wires.

The plastic housing is a regular fail point on these cars.

I lifted mine, and away she went. I was very relieved cos it was 106 f outside that day and I had a 6 hour drive ahead of me. Good luck

Since you've been reading older posts, you most likely found mine.

I had a motor go bad a while back (commutator/brushes were toast).

But I was able to replace it without moving the engine. Once you start taking things apart, you'll see that there is a removable piece on the blower housing. That will allow you to remove the motor/impeller assy. with the engine in place. Yes, it is a pain to get the screws out, but it is possible. IIRC, I removed spark plug wires to make the access easier.

Since STS has a firewall similar to an Eldorado, I assume that your procedure should be very similar.

But you should verify that it is the blower and not the control module that is bad.
Theoretically, you could remove the thick wire feeding power to the blower (from the control module) and first measure the motor's resistance. It should be few ohms (not open or shorted). Then, apply 12Volts to that wire and see if the blower spins. But be careful, if the impeller is jammed, the motor will be drawing lots of current! That can cause sparks and hot wires!

Peteski

(Edit-wanted to clarify I have a 1999 DeVille)
Well I finally got it after many cuts and scrapes on my hands (never loan out your tools) trying the rocking engine and forcefull persuasion method "didn't" work, I finally borrowed a neighbors jack (did I just say something about loaning tools?) dropped the two sub-frame bolts and "presto" went in slicker than vasoline and ......well you get the point.....for me anyway, the subframe was the way to go, could probally do it in less than an hour and a half now.
Just to review how I did it:
1. Place car on car ramps for easy access to subframe.
2. Disconnect battery
3. Remove coil pack,last 2 spark pug wires closest to the blower(cover holes with clean cloth),and black vacum assisted module(don't know what it's called but didn't want to break it,held in with one bolt)
4. I then removed the 2 ends of the "dogbones" connected to the engine.
5. Now place jack under front of subframe and loosen the 2 bolts on both sides about 2 inches, ( no need to completly remove). and allow to lower.
6. The old blower has three screws and one plug, should come right out no problem-remove and replace-just don't forget to add the new heat shield like me!
Reverse process to put it all back together, don't forget any wire you may have disconnected on coil pack, vacum whatever may have helped you get more room. This is just what I did for a "99" DeVille. Your results may vary and I know there is similar info in other threads but every little bit helps and like stated in other posts make sure it is the motor 1st.
Total Cost: $238.00+ tax (Advance Auto) About 3 hours if you don't know what your doing, and various cuts and scrapes. Good Luck, it really wasn't that bad with all the great info on this site. Bob T