Blower Just Stopped - PeachParts Mercedes-Benz Forum

Bob Albrecht · #1 07-10-2011, 08:19 AM

I had the car packed up for a road trip. Filled it up with biodiesel. Got in the car, drove 10ft. And the blower suddenly stopped.

The AC pump still engages when the AC is turned on.

There was no sign of blower motor wear.

No symptoms prior to this.

The fuses are all good.

No defrost or high fan settings get it to turn on.

If it is set to EC I can feel outside air coming in when the car is moving fast.

I had to transfer my family and all our stuff to our other car and head out. When I get back I want to fix it.

Any ideas on what it might be or what to check?

dablk1 · #2 07-10-2011, 09:02 AM

Be sure to check and recheck the 30amp strip fuse.

Bob Albrecht · #3 07-10-2011, 09:12 AM

I checked and re-checked the fuse.

It is not the fuse in the fuse box.

Is there another fuse somewhere?

dablk1 · #4 07-10-2011, 09:30 AM

No, it's not in the fuse box. There's another little black box 1x3 inches directly in front of the fuse box or very close to it. If you pop the cover off of it there is a 30amp strip fuse in there. Check to see if it has a crack in it.

leathermang · #5 07-10-2011, 09:41 AM

Quote:

Originally Posted by dablk1

No, it's not in the fuse box.

OOOOPPPPPSSSSSS... I might have waited till he was back home from his vacation to lay that one on him.... Let him enjoy his vacation and be happy he had a good running backup car to use as ' plan B '..... many people do not...
LOL

dablk1 · #6 07-10-2011, 09:58 AM

Lol

bbboomer · #7 07-10-2011, 03:53 PM

My 300SD just did the same thing. No warning no unusual sound, it just quit.
Checked the fuses, power at the motor plug is good and the a/c clutch engages etc.
The blower motor was toast. I had hoped to get by with replacing brushes but the armature was completely worn out.
A new Bosch motor should be here tomorrow.

warmblood58 · #8 07-10-2011, 05:58 PM

My SD just did this too and to cure the problem, I did two things. Pull blower motor and replace brushes -believe me, if your car has some miles on it, they all need new brushes, easy! More importantly and this is a known w126 issue, bypass fuse block (fuse for blower) and replace with a 30 amp strip fuse as too much resistance has built up in your system over the years. Many cars have already had this done and many more have not. Go to a PNP and find a remote fuse block out of any 126 car (mounted on firewall close to brake master) remove and wire to your car, took me 30 minutes and voila, instant blower again in my '82 300sd -you will be happy you did this! Good luck!

86-300sdl · #9 07-10-2011, 06:11 PM

Prior to replacement my blower would occasionally not work until I "jiggled" the ignition key right and left.

Bob Albrecht · #10 07-10-2011, 09:51 PM

The car only has 125K miles on it, but I anything can happen in a car this old. You should see my service log!

Thanks a lot for the help it gives me some things to look at.

All the other electrical stuff seems to be working.
Does the 30A fuse power anything other than that blower fan?

I will take a bunch of pictures and post them here.

dablk1 · #11 07-13-2011, 04:39 AM

Pull the blower and check it. Get the little black box at any junkyard for about maybe $2.

Bob Albrecht · #12 07-13-2011, 01:06 PM

Quote:

Originally Posted by dablk1

Pull the blower and check it. Get the little black box at any junkyard for about maybe $2.

My car has no glove box. There are some screws behind a little panel on the front of the knee bolster and a couple of screws and a plastic clip underneath the air bag.

I have the blower motor out now.

It looks fine. The brushes are not worn all the way down, but they do have some wear.

There seems to be some resistance in turning the motor. It doesn't seem to turn as freely as it should, but I don't know what normal is.

Maybe I should replace the motor. Is there some way to test if the bearings are OK?

dablk1 · #13 07-13-2011, 02:43 PM

You just checked it. It should spin somewhat freely. Some people have lubricated the bearings and have gotten more use. From the looks of your pictures, it seems like a seized motor could cause that.

Bob Albrecht · #14 07-13-2011, 03:09 PM

The motor does spin somewhat freely, but there is some resistance that is not from the fan.

I am inclined to think that the motor is the problem because my test wire started to warm up. I hate to spend the money if this isn't it.

funola · #15 07-13-2011, 03:32 PM

Was the lamp cord screwed down? If not, it wasn't making a good enough connection. Do you have an ammeter? My W123 fan draws 16 amps on high.