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.

Bio300TDTdriver · #11 07-10-2011, 10:39 PM

Quote:

Originally Posted by Bob Albrecht

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.

Just the blower motor.

Bob Albrecht · #12 07-11-2011, 03:46 PM

Does anyone have a picture of the 30A fuse for the blower?

Where do I get one?

Jeremy5848 · #13 07-11-2011, 04:06 PM

Quote:

Originally Posted by Bob Albrecht

Does anyone have a picture of the 30A fuse for the blower?

Where do I get one?

Here it is, mounted on the shock tower, between the shock absorber and the fender. You can get them from FastLane (click "Buy Parts" at the top of the page; they support this forum) or almost any 124 in an auto junkyard or from a dealer.

NOTE: The fuse is physically the same as the 80 Amp fuse in the preglow relay so don't confuse them. The blower takes a 30 Amp fuse; it will have "30A" stamped into the aluminum.

NOTE: The fuse is purchased separately.

Jeremy

Bob Albrecht · #14 07-11-2011, 11:34 PM

I found the 30A bare metal fuse online for $2. Is the fuse a common item that you can get at the auto parts store?

What causes he fuse to blow?

Is there a short somewhere?

Bio300TDTdriver · #15 07-12-2011, 12:20 AM

It probably depends on the store. I would think most could order it. The MB dealer should have it in stock.

Was it melted or cracked? If the motor seized up that would probably cause it to melt. Most of the strip fuse failures I've seen or read about were cracked from age and not from a fault with the motor.

There was an issue with the fuse box melting where the blower fuse was located. MB moved the fuse to the box outside the fuse box like it is in your car.

The brushes on the blower motors eventually wear, but usually give you a warning and don't just stop.