Here are some pictures of the fuse and the little box it is in.

The fuse looks like it might have been corroded, but then heated up for a long time and burned through. The plastic box had a hole melted in the bottom of it.

Should I check the blower to see if it is seized-up by bypassing the fuse for a second to see if the blower turns?

I found the plastic box and wires online for about $45, but I think I am just going to plug the melted hole with some epoxy putty.

Attached Thumbnails

   

__________________
1991 350SD (updated rods)
Biodiesel B100 when I can find it.
Dino when really cold outside

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

__________________
1995 E420 152k
1991 300D 2.5 348116 daily driver
1992 300E 2.6 196k-work in progress(head gasket)
2002 BMW 745Li 93k

Get an inline 30 A fuse that uses the common plug in fuse for a few $ at Autozone and forget about that fender mounted special strip fuse and be done with it.

__________________
85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Merits of strip vs ATC discussed in this thread, same application:

http://www.peachparts.com/shopforum/showthread.php?t=227627

In summary, strip fuse allows more heating before blowing. And a big hint, install the new strip with a slight curvature in it, not absolutely flat to allow for heat stressing.

__________________
Cheers!
Scott McPhee

1987 300D

More heating before blowing is not good, that's part of the reason that fuse block melted. Another reason for the melted block is plastic that could not handle the temp was used.

__________________
85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

I just used a piece of lamp cord and bypassed the fuse to see if the motor was seized or shorted.

The motor came on and sounded OK, but. the lamp cord started to warm up as I was holding it in place.

The fuse is supposed to blow at 30A x 12V = 360W. That much power should not be heating up a 110V lamp cord.

I am going to pull the blower motor and have a look. I need to find the thread for how to do it.

__________________
1991 350SD (updated rods)
Biodiesel B100 when I can find it.
Dino when really cold outside

That is the setup I've had for several years now. That and a new blower motor took care of my problems. We'll at least the no air flow problem.

Don't forget to clean the evaporator when you pull the blower motor.

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

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?

__________________
1991 350SD (updated rods)
Biodiesel B100 when I can find it.
Dino when really cold outside

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.

__________________
1995 E420 152k
1991 300D 2.5 348116 daily driver
1992 300E 2.6 196k-work in progress(head gasket)
2002 BMW 745Li 93k

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.

__________________
1991 350SD (updated rods)
Biodiesel B100 when I can find it.
Dino when really cold outside

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.

__________________
85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

The lamp cord wasn't screwed down, but it made a good connection. The wire should not have heated up that much in just a few seconds. The fan should draw no more than 360W of power.

I do have an ammeter.

Something caused the fuse to melt and it was quite hot for a long time because of the hole melted in the bottom of the plastic fuse box. The fuse probably was not corroded. The car is a garage queen.

I looked at the fan motor again this morning. It is not turning freely enough, although it is not seized.

Another motor and fuse are on the way. Parts Geek - $82

__________________
1991 350SD (updated rods)
Biodiesel B100 when I can find it.
Dino when really cold outside

Before I go pounding away at it, does anyone know the best way to detatch and re-attach the fan?

There is a clip on the other side of the motor, but it looks like the fan is firmly attached to the shaft.

__________________
1991 350SD (updated rods)
Biodiesel B100 when I can find it.
Dino when really cold outside

Current draw of the blower motor during normal operation would probably be closer to 200W. The fuse rating will be well above typical current draw. That being said, even 15 to 20 amps through lamp cord is a lot of current for the typical gauge wire found in that type of cord. Remember, even a 100w bulb in a table lamp will draw less than 1 amp of current.

The point of my blathering is that the cord being warm is not necessarily an accurate measure that the blower current draw is high.

__________________
Joe

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1980 300SD - 495k miles - 'The Ambassador'
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Former Family Members
95 C280
73 280SEL
90 300D
87 300SDL (X2)
86 560SEL
84 300D
80 300SD

Any ideas on how to remove the fan from the motor?

__________________
1991 350SD (updated rods)
Biodiesel B100 when I can find it.
Dino when really cold outside