Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 12-01-2009, 05:23 PM
snookwhaler's Avatar
Linesider
 
Join Date: Feb 2009
Location: Treasure Coast, FL
Posts: 1,417
Question Melting fuses again

This summer when I got my A/C going, my aux. fan fuse kept melting. It was not "blowing the fuse", but rather melting the plastic that supports the metal fuse. At the advice of the forum I pulled all the fuses cleaned all the contacts and applied dilectric paste to all the fuse tips. Problem solved.

Today my wife comes home and says that the A/C is not working and it is dead? So, I pop open the fuse box to find that the fuse for the A/C compressor and the blower fan is melted. The fuse is not blown but the plastic is melted (different fuse, but same problem as before). So, I cleaned the contacts again, applied the paste and put it back together. Everything works as before, but that one 25A fuse (#8) gets damn hot.

With the car running and the A/C running, fuse #8 gets warm with the fan on low, hot with the fan in Auto. and damn hot with the fan on high. I reached over and felt the blower resistor and it was cool to the touch. Not even warm. Plus the fan runs strong and makes no weird noises. But there is obviously some resistance somewhere? Any ideas?

I need to know where to get those ceramic fuses too...

__________________
AJ

1985 300D (SOLD)

Reply With Quote
  #2  
Old 12-01-2009, 05:29 PM
JHZR2's Avatar
Registered User
 
Join Date: Jan 2002
Location: New Jersey
Posts: 5,265
MB has a workaround for this. It is well known, and they relocate the fuse outside of the fuse box, on the front fender. I think then with a heavier wire, they apply a strip fuse of higher rating.

I had a nice smoke event once when I busted my fuse due to the blower...
__________________
Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (113k)
1991 350SD (206k)
1991 300D (228k)
1993 300SD (291k)
1993 300D 2.5T (338k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (265k)

Past Diesels:
1983 300D (228K)
1985 300D (233K)
Reply With Quote
  #3  
Old 12-01-2009, 05:33 PM
Registered User
 
Join Date: Nov 2004
Location: North central Texas
Posts: 2,596
It might be time for a new blower motor or cleaning/lubing the old current hog.
Reply With Quote
  #4  
Old 12-01-2009, 05:41 PM
snookwhaler's Avatar
Linesider
 
Join Date: Feb 2009
Location: Treasure Coast, FL
Posts: 1,417
Quote:
Originally Posted by Whiskeydan View Post
It might be time for a new blower motor or cleaning/lubing the old current hog.
I pulled the motor when I cleaned the evaporator a few months back. At that time I marked the shaft, pulled the squirrel cage, lubed the bushings and inspected the brushes. Everything looked fine, just a little dusty. This is why I find it hard to believe it is the blower motor. I guess I should pull it again though?

That is interesting about relocating the fuse. I would like to know more about that, as I do have a 126 aux. fan as well (much larger than the 123 fan). Maybe I should relocate both of those fuses? I just hate to mess with the original wiring harness.
__________________
AJ

1985 300D (SOLD)

Reply With Quote
  #5  
Old 12-01-2009, 05:44 PM
JHZR2's Avatar
Registered User
 
Join Date: Jan 2002
Location: New Jersey
Posts: 5,265
I think it screws into the leads from inside the fusebox, just bypassing that fuse and its old plastic holder.

Doesnt seem like much of a job or that much of a bypass, but solves the problem where it exists...

I think you can find info on it through the search. IIRC, there is even a DIY somewhere.
__________________
Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (113k)
1991 350SD (206k)
1991 300D (228k)
1993 300SD (291k)
1993 300D 2.5T (338k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (265k)

Past Diesels:
1983 300D (228K)
1985 300D (233K)
Reply With Quote
  #6  
Old 12-01-2009, 05:53 PM
::matthew's Avatar
Registered User
 
Join Date: Sep 2008
Location: Tallahassee, FL
Posts: 594
I got a MB fuse kit here, I believe...perhaps Phil can get you what you need.
__________________
1985 300D cali 190K

http://mercedes.thatchermathias.com/mw300d.jpg
Reply With Quote
  #7  
Old 12-01-2009, 06:03 PM
snookwhaler's Avatar
Linesider
 
Join Date: Feb 2009
Location: Treasure Coast, FL
Posts: 1,417
Quote:
Originally Posted by JHZR2 View Post
I think it screws into the leads from inside the fusebox, just bypassing that fuse and its old plastic holder.

Doesnt seem like much of a job or that much of a bypass, but solves the problem where it exists...

I think you can find info on it through the search. IIRC, there is even a DIY somewhere.
I'm not above searching. Thanks! I just have not gotten that far yet. This does make sense since it seems the whole fuse box in that area is getting hot.






Quote:
Originally Posted by ::matthew View Post
I got a MB fuse kit here, I believe...perhaps Phil can get you what you need.
Are those the ceramic ones!? Thanks!
__________________
AJ

1985 300D (SOLD)

Reply With Quote
  #8  
Old 12-01-2009, 06:20 PM
79Mercy's Avatar
Registered User
 
Join Date: Mar 2008
Location: Florida
Posts: 4,131
i have had cheapo plastic fuses melt before to, in fact many members have. Replace the plastic fuses for ceramic ones from the dealer.
__________________
1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg
Reply With Quote
  #9  
Old 12-01-2009, 06:46 PM
Banned
 
Join Date: May 2002
Location: Blue Point, NY
Posts: 25,396
Just install this device and your problem is solved:

http://www.performanceproducts4benz.com/product.asp?pf_id=P54-280&dept_id=5632

The p/n is: 54-280.
Reply With Quote
  #10  
Old 12-01-2009, 06:51 PM
JHZR2's Avatar
Registered User
 
Join Date: Jan 2002
Location: New Jersey
Posts: 5,265
yep, that's the one.
__________________
Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (113k)
1991 350SD (206k)
1991 300D (228k)
1993 300SD (291k)
1993 300D 2.5T (338k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (265k)

Past Diesels:
1983 300D (228K)
1985 300D (233K)
Reply With Quote
  #11  
Old 12-01-2009, 07:00 PM
DeliveryValve's Avatar
Chairman of my Benz
 
Join Date: Jun 2006
Location: Central California
Posts: 4,159
Quote:
Originally Posted by Brian Carlton View Post
Just install this device and your problem is solved:

http://www.performanceproducts4benz.com/product.asp?pf_id=P54-280&dept_id=5632

The p/n is: 54-280.
Why not from Phil?

part number 126 540 30 13

http://catalog.peachparts.com/item.wws?sku=W0133-1619012&itempk=85830&mfr=OES%20Genuine&weight=0.10

BTW - IMHO, I would not install this 30 amp fuse link on a pre-'85 w123 with a blower that requires a 16 amp fuse. Fires can possibly happen.


.
__________________
1983 123.133 California
- GreaseCar Veg System


Reply With Quote
  #12  
Old 12-01-2009, 07:06 PM
Banned
 
Join Date: May 2002
Location: Blue Point, NY
Posts: 25,396
Quote:
Originally Posted by DeliveryValve View Post
Why not from Phil?

part number 126 540 30 13

http://catalog.peachparts.com/item.wws?sku=W0133-1619012&itempk=85830&mfr=OES%20Genuine&weight=0.10

BTW - IMHO, I would not install this 30 amp fuse link on a pre-'85 w123 with a blower that requires a 16 amp fuse. Fires can possibly happen.


.

Thanks for that link.

The last time I called Phil and asked about this product, he stated that Fastlane has nothing like it. Therefore, I have been recommending the PP equivalent since that conversation (about two years ago).
Reply With Quote
  #13  
Old 12-01-2009, 07:13 PM
snookwhaler's Avatar
Linesider
 
Join Date: Feb 2009
Location: Treasure Coast, FL
Posts: 1,417
Quote:
Originally Posted by DeliveryValve View Post
Why not from Phil?

part number 126 540 30 13

http://catalog.peachparts.com/item.wws?sku=W0133-1619012&itempk=85830&mfr=OES%20Genuine&weight=0.10

BTW - IMHO, I would not install this 30 amp fuse link on a pre-'85 w123 with a blower that requires a 16 amp fuse. Fires can possibly happen.


.
What is the deal with the fuses anyway? I see that Phil has all I need and I WILL buy them from here. They show a kit with 9 fuses for $11.88. Or you can buy them individually for $.29. When you can buy 9 individually for $2.61 what is the point of the kit? Is the quality of the fuses that much different? Or are you just buying it for the logo and the container? I remember reading somewhere that the MB fuses were crap because of the Aluminum and the problem with corrosion on the fuse block (dissimilar metals). Or was that the original "older than dirt" fuses?
__________________
AJ

1985 300D (SOLD)

Reply With Quote
  #14  
Old 12-01-2009, 07:41 PM
DeliveryValve's Avatar
Chairman of my Benz
 
Join Date: Jun 2006
Location: Central California
Posts: 4,159
Quote:
Originally Posted by snookwhaler View Post
What is the deal with the fuses anyway? I see that Phil has all I need and I WILL buy them from here. They show a kit with 9 fuses for $11.88. Or you can buy them individually for $.29. When you can buy 9 individually for $2.61 what is the point of the kit? Is the quality of the fuses that much different? Or are you just buying it for the logo and the container? I remember reading somewhere that the MB fuses were crap because of the Aluminum and the problem with corrosion on the fuse block (dissimilar metals). Or was that the original "older than dirt" fuses?
I don't know any info on the "kits" vs individuals fuses. But as far as what type of fuse you should be looking for are the ceramic bodies with a copper fuse strip. Not aluminum. Copper are the versions to get.



.
__________________
1983 123.133 California
- GreaseCar Veg System


Reply With Quote
  #15  
Old 12-01-2009, 08:21 PM
compress ignite's Avatar
Drone aspiring to Serfdom
 
Join Date: Feb 2004
Location: 32(degrees) North by 81(degrees) West
Posts: 5,554
Blower Circuit Wiring (Wire Size,AWG or Metric)

Other than the Pre-Disposable Environmentally Friendly Self-Degrading Wiring
Harnesses Mercedes required of their supplier in the middle '90s...Most wiring
is of good quality...BUT...of too small a gauge for the load (Amperage).
The Blower Fan Circuit Wiring is especially Plagued with this problem.
(Too Small a Wire Gauge RAISES the inherent RESISTANCE in the Circuit!)
The "Outside the Fuse Box" 30 Amp Aluminum Fuse is a "Work Around".
As the Blower Fan ages it requires more and more Power to do it's job.
(Lack of Bearing Surface Lube,Bruch wear,Etc.,Etc.)
What may have well been acceptable Wire sizing with a Fresh New Blower
is often overcome later by the above.

'Fuses? these are what you want.
Attached Thumbnails
Melting fuses again-screenhunter_01-dec.-01-20.27.jpg  

__________________
'84 300SD sold
124.128

Last edited by compress ignite; 12-01-2009 at 08:28 PM.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 11:44 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page