Weird BLOWER MOTOR problem - please read

[DJ SHO]

My blower motor has been working intermittantly for a week now. It seems it won't turn at all when it had been extremely cold out the previous night, like around 0º. But then it'll work later in the day once it warms up to a whopping 20º. Woohoo . I replaced the blower control module and no change. If you change the speed on the eatc head unit, you can hear the relays click in the BCM, so I know that's working right, but no motor. The weird part is, the other night it only went down to about 20º, I went out in the morning, turned the car on, NO MOTOR. Later that afternoon, it was around 26º or so, and the motor worked. But it usually doesn't work, like I said, when it was really cold out the night before. Could it be a dead spot or something in the motor? I bought a used one yesterday cheap, and before I go tearing into the system, I just wanted to get some thoughts on this. Thanks. Sorry so long, but this problem is starting to be a major P.I.T.A.

 

[jelloslug]

It really sounds like the blower motor. Its not really that hard to change though, it comes out through the glove box.

 

[projectSHO89]

If you want to make a check before slapping the motor in there, connect a meter across the motor leads and see if you're getting power to the motor when it is supposed to turn on but is not running.

If you confirm that you have power but the motor does not turn, that would indicate that the motor is the culprit.

Steve

 

[sdpatt]

What setting on the ECC unit are you trying? If only using AUTO, the blower will not blow at full speed until the engine coolant warms up enough to blow hot air. If this is occurring on VENT and FLOOR, then something is wrong.

 

[DJ SHO]

sdpatt:
What setting on the ECC unit are you trying? If only using AUTO, the blower will not blow at full speed until the engine coolant warms up enough to blow hot air. If this is occurring on VENT and FLOOR, then something is wrong.

Scott, it happens using any function on the head unit (vent, auto, def, doesn't matter). I've never seen a problem like this before. I've read the symptoms of the system when the BCM goes bad, but this show's none of those symptoms. It's erratic and really pi$$ing me off. If you turn the car on (not start it so you can hear the system working), you wait a couple seconds for the system to get going, you move the fan speed control to full speed and all you hear the little relay in the bcm click. And click again when u bring the speed down. No motor. Nothin. But go out later in the day and WALAH! Full motor, no problems. I mean what else could it be other than the motor? The BCM was swapped out and still the same problem. The head was changed back in Nov to a newer unit from a 95 because my buttons were all cracked, but that shouldn't have anything to do with it. This problem started last Fri. The only other possible thing I can think of is that there is some corrosion on a connector or wire or something, that is being the culprit in the changing temps/humidity in the car. Possible you think? I guess the only way to find out is put the other motor in, and see if I have the same problem.

<small>[ January 31, 2003, 02:15 PM: Message edited by: DJ SHO ]</small>

 

[DJ SHO]

Bump


Any other thoughts?

 

[projectSHO89]

Have you made the very simple test that I recommended or were you hoping for diagnosis by osmosis?

Steve

 

[DJ SHO]

Nice attitude.

Yes there's power to the motor. It works when it wants to. Maybe you didn't read my description too well. It doesn't like to work after it has been really cold the night before. I'm guessing the motor is just f'ed up. Since no one has a clue of this problem, and since there's no posts of a similar problem anywhere, I guess it's trial and error this time.

 

[projectSHO89]

As pointed out in my original post, if you have verified that there is power to the motor leads when it is supposed to be running, then the motor is indeed bad.

Not making a simple check to confirm or disprove a diagnosis means you're just continuing to guess.

 

[FAST4DR]

You are not alone. My old 91 that I used to have would do the same thing. Sometimes I would get in and the blower motor would not come on. I beat on the blower box below under the glove compartment and that would get the motor running and then it would work fine for a few days and then it would do it again. I guess the motor brushes or whatever were going bad. I fixed it by trading the car in on a 93. hahahaha

 

[NotSoSlowSHO]

Okay everyone... a quick lesson on electric motors

Your typical electric motor is a very simple design and requires little to no maintenance. However, every motor will eventually fail. Here are the most common faults for failure:

Excessive bearing wear
By far the most common cause of motor failure... Im sure I dont have to explain it further wink

Mechanical Overload
when a motor is under a heavy load for a long time the the motor will eventually fail from mechanical overload. The stator's insulation actually burns up and the motor windings are irreversibly damaged.

Locked rotor
The most severe damage accurs to a motor when the rotor siezes. A mechanical failure in the system is normally the cause. (think: sticking a branch in the spokes of a bycicle tire ) Normally a locked rotor results in damaged motor windings

Low voltage
low voltage can cause excessive current in the windings when the motor is under load. This will burn the windings.

Single phase condition
applies to 3 phase motors. a single phase condition occurs when a 3 phase motor loses one of it's 3 lines due to an open or blown fuse. If the motor is running at the time it will continue to run. However, there will be an increase in current in the 2 remaining lines. This will damage the motor.



remember, temp. plays a BIG role in the flow of electricity. And how electric motors operate.

I think that either your motor bearings are shot (or at least bad enough that there is enough binding in very cold weather that they inhibit the operation of the motor)

or,

the motor's rotor is damaged and it slighty binding on the brushes (if applicable) and the case.

Or maybe a bit of both. (IF IT IS INDEED THE ,MOTOR)

wink

 

[30footSHO]

Well, guess what?

I have just started having this EXACT same problem today. It was about -7 degrees out when I started the car, and it still hasn't warmed up enough to get the blower working.

Interestingly enough, I shut off the EATC last night, instead of leaving it running like I usually do. Perhaps that has something to do with it? Also, I thought my motor was going bad before, but when I topped off the coolant, it magically started working again. WTF is with these cars?

It's a love/hate relationship, I guess...

Anyone else have these problems and want to share their tips/tricks/experiences?

Dave

 

[DJ SHO]

I've got another motor, but maybe I'm just waiting for the coldest day of the year to put it in?

Well not that it's a good thing that your blower motor is acting funny too, but at least I don't feel like a loner out here all by myself with this weird ass problem. I'm going to put the new motor in this week and keep an eye what happens. If the new one does the same thing, then I'm gonna blow the car up

<small>[ February 10, 2003, 11:54 PM: Message edited by: DJ SHO ]</small>

 

[30footSHO]

If you're gonna blow the car up, can I have your wheels?