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 > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 06-01-2006, 12:18 AM
Befuddled
 
Join Date: Jun 2006
Location: Oregon
Posts: 8
300E... Sick Alternator

I have a 1989 300E, and we're on to its third alternator. Is there a way of replacing the stock alternator with a high amperage unit?

Reply With Quote
  #2  
Old 06-01-2006, 01:17 AM
haasman's Avatar
Registered User
 
Join Date: Jun 2001
Location: San Francisco, CA
Posts: 3,097
Are you sure it is a bad alternator and not the small voltage regulator attached to the unit on the back side?

Haasman
__________________
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)
Reply With Quote
  #3  
Old 06-01-2006, 01:24 AM
carson356
Guest
 
Posts: n/a
Quote:
Originally Posted by Jim Marshall
I have a 1989 300E, and we're on to its third alternator. Is there a way of replacing the stock alternator with a high amperage unit?

what brand are you using?
Reply With Quote
  #4  
Old 06-01-2006, 02:04 AM
GVB GVB is offline
Registered User
 
Join Date: May 2006
Posts: 178
Bosh has really bad alts. If I have to use a Bosh, I order 2 just in case. Make sure your batt. is ok though. An alternator will not charge a bad Batt.
Reply With Quote
  #5  
Old 06-01-2006, 02:18 AM
carson356
Guest
 
Posts: n/a
Bad bosch? speaking from a shop stand point where we replace several a year, during the past year we have only seen 2 bad bosch reman units, i think that is pretty good,
the one thing i think is bad is that they use used regulators, they do install new brushes, but the regulators have been the cause for the failures we have seen with the reman units.
Reply With Quote
  #6  
Old 06-01-2006, 02:24 AM
GVB GVB is offline
Registered User
 
Join Date: May 2006
Posts: 178
Yeah, bad bosh. The quality of bosh has gone down hill for the past eight years or so. The one that I took to my mom and pop's alt shop that I use for specialty needs, was a bad armature. Go figuar, huh.
Reply With Quote
  #7  
Old 06-01-2006, 11:27 AM
Zeus's Avatar
Moderating, Eh?
 
Join Date: Feb 2000
Location: Canada
Posts: 1,774
Quote:
Originally Posted by Jim Marshall
I have a 1989 300E, and we're on to its third alternator. Is there a way of replacing the stock alternator with a high amperage unit?
Jim -

If your 300E has the stock 70A Bosch alternator, I would definitely upgrade it. I upgraded mine to the 80A Bosch AL66X alternator. It's not just the fact that it outputs an extra 10 amps, the 80A version is much more efficient at lower RPMs.

I've posted info from one of my previous posts below -

Quote:
Originally Posted by Zeus

The problem has been solved! Thanks again to everyone who replied and once again, to this forum in general.

I replaced my ailing stock 70A alternator with a new Bosch 80A (66X) alternator. All symptoms are gone now. Cars runs perfectly.

I did some before and after battery multimeter readings right before I did the swap -

BEFORE (70A):
rest - 12.85V
idle - 13.86V
idle with full load = 11.87V
full load, 1500 RPM = 11.74V

AFTER (80A):
rest = 12.88V
idle = 13.97V
idle with full load = 13.56V
full load, 1500 RPM = 13.94V

A few other unexpected pleasant surprises awaited me as well - I had an annoying flicker of my instrument panel lights at idle - totally gone. Lights are all nice and bright. The monowiper now zips across the windshield crisply and the washer jets spray properly.

It was easy to install the new alternator. 2.5 hours total. Old one came off easily and I took it off without removing the serpentine belt. I loosened (but not removed) the fan shroud and I just loosened the two mounting bolts (13mm) and the old alternator slipped out. I cut the old wiring harness near the base and there were three wires - two 10 gauge wires and one smaller (16 gauge?) wire. I soldered new eyelet connectors to each wire and sealed with heatshrink. The 80A (Bosch 66X)alternator doesn't have a plug in harness, it has a large bolt and a small bolt to attach the wiring (see picture here in the Fastlane catalog). The two large wires go to the large bolt and the small wire to the small bolt. That's it - thanks to M.B. DOC for that info in another post!

To install the new alternator, I slipped it roughly into place and got the belt on the pulley first. I then attached the upper mounting bolt. Then, from underneath the car, I pulled down hard to get the alternator into place for the lower mounting bolt. It took some strength, but I'm no Hercules (no pun intended) and it wasn't that hard. I had the lower bolt ready in place, so once I had leveraged the alternator into position, I slipped the bolt home and tightened it. That's it, no removal of the belt necessary - not sure if everyone is this lucky, I'd hate to mess around with the tensioner. Belt tension is fine (and the serpentine belt is in good condition in my car, btw).

So that's it, I've got a new alternator, a happy Benz and a great new project to look forward to - installing my new Alpine amp. That's a post for another section though. Life is good!

Thanks again to all!

Chris
More info, courtesy of M.B.DOC -

Quote:
Originally Posted by M.B.DOC

The charging system on the 1986-89 W124 chassis is under-powered. IN 1990 MB installed a much more powerful alternator. AT dealer & many indenpendant shops that early 65-70A alternator is replaced by the later 80+A alternator. The only part needed to install the larger alternator is the wiring loom MB part number 124-543-45-26. The alternator is 008-154-48-02-88 OR Bosch AL66X
__________________
Chris
2007 E550 4Matic - 61,000 Km - Iridium Silver, black leather, Sport package, Premium 2 package
2007 GL450 4Matic - 62,000 Km - Obsidian Black Metallic, black leather, all options
1998 E430 - sold
1989 300E - 333,000 Km - sold
1977 280E - sold
1971 250 - retired


"And a frign hat. They gave me a hat at the annual benefits meeting. I said. how does this benefit me. I dont have anything from the company.. So they gave me a hat." - TheDon
Reply With Quote
  #8  
Old 06-02-2006, 06:00 PM
Befuddled
 
Join Date: Jun 2006
Location: Oregon
Posts: 8
Bad alternator revisited

It was a Bosch rebuilt and it was installed with a new battery.

I like the idea of a heavier duty alternator. Of all the cars anc company vehicles I have owned this is the only one that I have replaced an alternator.

Jim

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 05:13 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, 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