Edit: Unplugging the connector to the blower fan solved the draining battery problem for now but obviously is only a temporary fix for the battery.

 

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the electronic speed controller built into the blower is bad -
replace the blower motor -

I recommend the FOUR SEASONS 35121 - $95 - with free shipping
http://www.ebay.com/itm/112258590740?rmvSB=true

or $100 on amazon -
https://www.amazon.com/Four-Seasons-Trumark-35121-Blower/dp/B000C2Q1TA

 

It's built in? Not a separate module?

 

Would that cause the motor to run all night when the car is off?

 

Yup. Control module, as stated, is built onto the blower motor. Four seasons, or try your luck at a yard. You will have to remove a few items from the rear valve cover, plus remove the module from the squirrel cage, to remove it. Install in reverse order. Good luck.

 

https://m.youtube.com/watch?v=e-KQjwnehgY I found this video, does this motor that you linked also break down into 3 pieces?

 

Having literally changed my blower 2 weeks ago I can tell you the 4 Seasons blower sucks to put in. Had to take the motor apart and reassemble in place. The OEM is much easier to replace, I'd personally get a used for the amount of trouble it was. If just need the control head it'll be even easier than taking motor and squirrel cage out.
The IPC display has gone out and you can swap a known good display(only display not the whole IPC) without needing to reprogram the IPC. No hard to take apart, hard part getting it out as dash has to come out.

 

If I go to a junkyard or find one used, how can I test to be sure it is in working order?

 

Take a battery to put in to check IPC, as the blower ONLY works if car is running. Other than that it's a crap shoot(get a warranty). I check the blower before installing in my car(plug in on engine and start car see if blower works).

 

I really appreciate all the input here! I am going to the junkyard first thing tomorrow. I am going to try my luck with just replacing the control head piece, as I am fairly certain that is all that is bad. Figure it's worth a shot at the yard and they list having 4 devilles from 1994-1999 in the yard right now. It'll be good practice removing the parts from a car there too. I also need a new power antenna so I'll be checking for that too!

 

What rodknock said. Most yards will let you plug it in to make sure it works. Try to find the cleanest looking blower motor among the wrecks. I had to pull 3 before I found a good one. First one I removed locked up while spinning by hand. Second one started popping as soon as I powered it on. I ended up finding a really clean deville that probably popped a hg with low miles. Everything but the engine had been stripped clean, but the blower motor and a brand new purge solenoid that I needed was still there.

 

I must have missed your post. Yeah heading to the yard to try for a second motor now before they close. Hopping the '99 they have still has the motor.

 

Pulled both parts from another Deville. This motor does not turn at all. Luck didn't pan out :/ can return for 30 days at least. Really don't want to have to spend $100 on a new one.

 

I'm gonna hit the junkyard one more time before they close and try again. Also, I'm not sure what people are talking about when they complain that there is no clearance. Once the coil packs and wires are out of the way everything came out and went in with ample room. Maybe the aftermarket one is more difficult?

 

I also own a '98 DeVille, and several times now have come back to the car a little while after driving it somewhere and found what sounds like a blower motor under the windshield wiper area to be running on it's own with car off, no keys in the ignition... what the heck? I always try to make sure I turn the A/C OFF before I get out of the car, and that seems to help, but did it again today. Is this the same thing that is happening to yours Zachary? Sorry, what is the "IPC Display" - Jon

 

In my car the blower motor stopped working randomly, the air would sometimes blow sometimes not but a whisper. That is also when it started staying on overnight and killing the battery. Waiting for the a new blower motor to arrive in the mail. Ran out of the cars to pull from in the junkyard after 3 tries

 

DIC = Driver Information Center or IPC = Instrument Panel Cluster is politically correct millennial speak for "instrument panel".

For correct terminology, use the "Acronyms" sticky on this Deville forum home page.

Some of these cars came from the dealership (new) with HVAC Afterblow enabled. It's a resettable feature (dealership) that runs the HVAC blower for a while after shutdown to dry out the ducting, this preventing mold and mildew. The blower should come on after you get out of the car and run for several minutes, then stop.

 

Alright, here is where I'm at now. I just got the four seasons motor in the mail. The car was already apart so I plugged it in and turn the key to turn the air on and the motor is not spinning at all. I also have one of the motors from the junkyard and plugged it in, the used motor turned on for a few seconds and then shut off. Neither one is functioning properly. Is there anything I can check. The plug to the motor is showing 12v too.

 

There is a multiple ground point outside the passenger right foot carpeted kick panel - fender inner panel. A bunch of dash grounds collect there and go into a black box that is studded to body metal. Clean the whole mess and stud. Cross your fingers. Some members have even soldered individual ring terminals to the ground wires and eliminated the collector box.

 

I just found out the hard way that the car needed to actually be running to engage the HVAC motor.... installed the new motor and all seems to be well.

 

I have a 97 Deville with a blower motor that stops at random times. could the problem be the module with the buttons? I have this left over from my ipc replacement . could these go bad? this module has a circuit board on it, so was thinking it is this?

 

I have a 97 Deville with a blower motor that stops at random times. could the problem be the module with the buttons? I have this left over from my ipc replacement . could these go bad? this module has a circuit board on it, so was thinking it is this?

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the problem COULD be caused by several things -
worn/loose plug - worn/loose ground - worn out motor - etc -
the programmer is probably the LEAST likely cause -

 

Those are pretty much just buttons, the hvac computer is under the dash, very reliable. Sure sounds like blower going out to me also, my 97 did the same thing.

 

If anyone needs a OEM blower motor, I will sell one I pulled from the yard that works.

 

Did u try just resolving the blower motor control module?