Blower Fan Stuck On - Burned Electrical Smell - 1993-850

[Ozark Lee]

What is curious from your original post is that the blower actually shuts off with the key and that the rec and A/C lights don't work any more.

The ECC itself turns off with the key but the blower fuse is always on. Most of the times when the power stage shorts out the blower continues to run even with the key off.

Something you can do that won't cost you anything and help with the diagnosis is to pop the ECC control head out of the dash and look for apparent damage. The ECC units have a tenancy to blow up fairly frequently but they normally leave trace evidence in the form a a blown up capacitor, a burned spot on the circuit board, and a big black smudge mark on the top of the inside of the case.

The way I get the control head out is to pop the radio out, you really don't need to remove the wires but if you do make sure you have the radio code, and then reach behind and then pop the controller out by reaching in from behind out pushing it out of the dash. It will resist a bit a first then then release.

Once it is out take off the upper housing and look for damage.

The more information that we have the more we can look like geniuses.



...Lee

[Ozark Lee]

I removed the lower dash panel on the passenger's side but now Glovebox won't come out. Forum post said "Next to the glove box door side of each of the arms there is a small hole. Slide the screwdriver into the hole and it will release the arm." This didn't work. Instructions don't say how far and how hard to push. I certainly don't want to poke all the way through. It's a very narrow hole by the way. Am I supposed to feel something, hear a click or what? Are 93's different?

I don't have a '93 but I don't think so. The screwdriver should be small and you will not hear a click or anything. Depress a vary small screwdriver into the holes and lift on the arm. Once you get to the "sweet spot" it should release unless some other knuckle head glued them in place (not unheard of but fairly rare).

...Lee

[Paul-93-850]

Simply depressing a jewelers screwdriver into the micro hole had no effect so I removed the screws that hold the glove-box door itself together. It's like a sandwich with an inside and an outside, hollow in the middle. Splitting it apart lets you release it from the inside as opposed to poking a screwdriver into the hole and hoping that something miraculous happens. My approach lets you see exactly what you are trying to accomplish, it becomes obvious. You also get to use a larger screwdriver which can push the plastic clip flush towards the arm allowing it to release. As these plastic clips age they become harder and more difficult to release.

[Paul-93-850]

What is curious from your original post is that the blower actually shuts off with the key and that the rec and A/C lights don't work any more.

The ECC itself turns off with the key but the blower fuse is always on. Most of the times when the power stage shorts out the blower continues to run even with the key off.

Something you can do that won't cost you anything and help with the diagnosis is to pop the ECC control head out of the dash and look for apparent damage. The ECC units have a tenancy to blow up fairly frequently but they normally leave trace evidence in the form a a blown up capacitor, a burned spot on the circuit board, and a big black smudge mark on the top of the inside of the case.

The way I get the control head out is to pop the radio out, you really don't need to remove the wires but if you do make sure you have the radio code, and then reach behind and then pop the controller out by reaching in from behind out pushing it out of the dash. It will resist a bit a first then then release.

Once it is out take off the upper housing and look for damage.

The more information that we have the more we can look like geniuses.



...Lee

BINGO!
A burned spot on the ECC board! Looks like a component vaporized. How much is this part used or new?

[Ozark Lee]

Check ebay, they tend to go in the $50 to $70 dollar range - as is the case with everything ebay it is sometimes a tad lower and sometimes a tad higher. You should be able to score one for under $100.

One other resource is JordanVW over on Volvospeed. He parts a lot of cars and he is fair and honest. At least he has been with me.

...Lee

[jgray850turbo]

Hi Lee,
In the middle of this thread Paul talked about the fan turning 'freely'. Is there a way to test the draw that the fan is creating to be sure if it's good?
My blower stoped working suddenly, without any noises or warning. I have the ECC and it doesn't work on any speed. The ecc still controls the temp and direction of flow, so I'm thinking that is fine. I removed the blower fan and it spins pretty smooth and doesn't seem to wobble or make noise, but I would think it should spin a little easier or more freely. I used jumpers direct to the battery and was surprised by the amount of torque it created, after I got a better grip and held the wire to the blower it spun very fast.
I'm pretty sure I should just replace the power stage, but if I can use a multimeter to test the blower draw, it would make me feel better. Your thoughts?
Thanks, Jeff

[BEJinFbk]

You can use an ammeter to check current draw.
The only problem is that most basic DMM's max
out at 10 or 11 amps. The motor will draw more
like 15 to 25 and you'll blow the ammeter fuse
in most handheld Digital Multi Meters.

A guerilla method is using an inline fuse holder
for testing and gradually increasing the fuse rating.
But, it could also be bearings, brushes going out or a
bad connection between the power stage and the motor.

I'd think about relubing the bearings, having a look at the
connections for signs of heat and keeping a fresh motor around.

[jgray850turbo]

Thanks BEJinFbk,
do I need to install the blower to test it or can I bench test? Also, you did see that my blower did not work at all in the car, it only spun when I hooked it direct to the battery? I should have also pointed out that along with code 4-1-1, I did get code 4-1-8 (no control signal to ecc power stage).