Help! Blown fuse is killing me - PeachParts Mercedes-Benz Forum

augusta · #1 09-06-2006, 05:48 PM

I have a 1979 300 sd (116). The brushes on the blower motor went bad. I put in a new motor. Before the brushes went bad it never blew a fuse

It will now run for a few hours and then blow #3 fuse.

I have done the following:

1) cleaned the fuse holder contacts
2) put in new mercedes fuses
3) disconnected the aux water pump
4) cleaned the ground connection
5) took the new fan out and re-unstalled it.

My #3 fuse is a 16 amp fuse....that is what the paper on the top of the fuse box says it should be. An old thread stated that his 79 300sd had a 25 amp fuse in #3. Am I putting in the wrong amp fuse??????What else could be causing this.

Thanks for your help

Augusta

Lostyankee · #2 09-06-2006, 08:14 PM

Just looked uner the hood and my 79 300SD fuse sheet says #3 is 16 amp.
No clue as to your problem ... a short somewhere?
Next time your near a vacuum cleaner repair shop, pick up new (spare) brushes for your blower for a bit cheaper than MB$.
Good luck.
Not too many 116's still around.

augusta · #3 09-06-2006, 09:56 PM

Thanks for looking lostyankee.

It maybe a short, but I don't understand why it didn't show up until I got a new blower motor and it happens after the car is driven for a hour or two.

A thought I had was that the new motor draws more amps than the old one. I have no idea why it would.

Thanks again

Augusta

Noeljb · #4 09-07-2006, 07:45 PM

Could it be in movng the wire around to replace the blower motor a wire that was brittle, broke and now it is shorting out?

Just a guess.

david s poole · #5 09-08-2006, 10:33 AM

the 16amp fuse was underated for a blower that can draw 25-30 amps.try a 25amp and i think all will be fine.if it blows then you have a problem and can start diagnosing.