55 amp alternator to replace 35 amp ? - Mercedes-Benz Forum

 
LinkBack Thread Tools Display Modes
post #1 of 5 (permalink) Old 12-28-2014, 07:37 AM Thread Starter
w108,107 Parts Hoarder
 
Fonzi's Avatar
 
Date registered: Jun 2010
Vehicle: 4Keep:450slc5.0cab 280sl5sp 280se4.5 500seAMG 2sell:500sl92 380se83 300se86 350sl4sp 75slc MorInSig
Location: Philadelphia Area
Posts: 18,754
Mentioned: 27 Post(s)
Quoted: 1621 Post(s)
Lifetime Premium Member
Garage
(Thread Starter)
55 amp alternator to replace 35 amp ?

The battery isn't charging in my 1972 250c which apparently should have a 35 amp alternator, just like my 1970 250c parts car. I happen to have two 55 amp alternators from 1972 350sl 4.5 cars sitting around. All of these used alternator options seem like they would possibly work, and the 35 amp would be the safer bet probably. However, I wonder if the 55 amp would be better to charge a larger battery and not cause any wiring problems. Just curious of the thoughts of the smarter people.

.

My signature:
Click for list of my 32 MB since 2010. If, you want 70's-80's Mercedes tuner wheels, let me know.
Fonzi is offline  
Sponsored Links
Advertisement
 
post #2 of 5 (permalink) Old 12-28-2014, 08:46 AM Thread Starter
w108,107 Parts Hoarder
 
Fonzi's Avatar
 
Date registered: Jun 2010
Vehicle: 4Keep:450slc5.0cab 280sl5sp 280se4.5 500seAMG 2sell:500sl92 380se83 300se86 350sl4sp 75slc MorInSig
Location: Philadelphia Area
Posts: 18,754
Mentioned: 27 Post(s)
Quoted: 1621 Post(s)
Lifetime Premium Member
Garage
(Thread Starter)
Oops. Forgot the pics from autohausaz
55 amp alternator to replace 35 amp ?-imageuploadedbyautoguide1419781541.224496.jpg
55 amp alternator to replace 35 amp ?-imageuploadedbyautoguide1419781556.070004.jpg
55 amp alternator to replace 35 amp ?-imageuploadedbyautoguide1419781567.120047.jpg

.

My signature:
Click for list of my 32 MB since 2010. If, you want 70's-80's Mercedes tuner wheels, let me know.
Fonzi is offline  
post #3 of 5 (permalink) Old 12-28-2014, 08:59 AM
Lifetime Premium Member
 
Scoot's Avatar
 
Date registered: Oct 2002
Vehicle: 1967 250 SL, 1963 220Sb
Location: Los Angeles / Altadena
Posts: 2,590
Mentioned: 3 Post(s)
Quoted: 103 Post(s)
Lifetime Premium Member
Have you determined that the alternator is bad? I'm not very knowledgeable on charging systems but I think that you can increase the alternator power and that as long as the voltage regulator is happy with it then there isn't a problem. On my 85 300TD it was a matter of replacing the diode on the back of the alternator, which I don't remember how I did.

Currently: 1967 250 SL, 1963 220Sb, 1965 300SE Lang, 1971 280SE parts car, 1972 Alfa GTV, 1965 Alfa Duetto, 1993 BMW R100R
Past: 1971 250 C, 1985 300 TD, 1967 250 S, 1968 280 S,1981 300 D, 1982 280CE, 3 Facel Vegas, Borgward Isabella Coupe, Alfa 2600 Sprint, Volvo P1900 (yes), numerous less interesting Volvos, ...
Scoot is offline  
post #4 of 5 (permalink) Old 12-28-2014, 09:24 AM
BenzWorld Member
 
Date registered: Aug 2006
Vehicle: 1998 SL500, 2010 GLK 350, 1972 300SEL 4.5, 1971 280SL, 1970 300SEL 6.3
Location: Midlothian, VA
Posts: 326
Mentioned: 0 Post(s)
Quoted: 37 Post(s)
You should be fine. I replaced my 35 amp alternator in my 1971 280SL with the 55 amp. Direct fit, same connector and as long as your voltage regulator is working not problems with overcharging.
Will
Baybear is offline  
post #5 of 5 (permalink) Old 12-28-2014, 11:07 AM Thread Starter
w108,107 Parts Hoarder
 
Fonzi's Avatar
 
Date registered: Jun 2010
Vehicle: 4Keep:450slc5.0cab 280sl5sp 280se4.5 500seAMG 2sell:500sl92 380se83 300se86 350sl4sp 75slc MorInSig
Location: Philadelphia Area
Posts: 18,754
Mentioned: 27 Post(s)
Quoted: 1621 Post(s)
Lifetime Premium Member
Garage
(Thread Starter)
55 amp alternator to replace 35 amp ?

Quote:
Originally Posted by Scoot View Post
Have you determined that the alternator is bad?

I actually have not. I should do some tests, and will look at the wiring diagrams next.

When I realized that the 4.5 m117 starter is the same as the m130, I realized I should take a look at whether the alternators I have laying around loose might be easier or better to use than the one in the parts car.

Quote:
Originally Posted by Scoot View Post
On my 85 300TD it was a matter of replacing the diode on the back of the alternator, which I don't remember how I did.

I can probably take the wiring out of the 1970 parts car pretty easily. So I will probably give this a try (after looking at the wiring diagram). Thank you!


Quote:
Originally Posted by Baybear View Post
You should be fine. I replaced my 35 amp alternator in my 1971 280SL with the 55 amp. Direct fit, same connector and as long as your voltage regulator is working not problems with overcharging.
Will

Awesome. I found some general info on the net that seemed to say the same. So the only info to determine would be if it's a direct bolt-on replacement as it appears. Now you've even confirmed this for me. Thank you!!

.

My signature:
Click for list of my 32 MB since 2010. If, you want 70's-80's Mercedes tuner wheels, let me know.

Last edited by Fonzi; 12-28-2014 at 11:11 AM.
Fonzi is offline  
Sponsored Links
Advertisement
 
Reply

  Mercedes-Benz Forum > General Mercedes-Benz Forums > Vintage Mercedes-Benz

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











  • Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
     
    Thread Tools
    Show Printable Version Show Printable Version
    Email this Page Email this Page
    Display Modes
    Linear Mode Linear Mode



    Posting Rules  
    You may post new threads
    You may 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 Off
    Trackbacks are On
    Pingbacks are On
    Refbacks are On

     

    Title goes here

    close
    video goes here
    description goes here. Read Full Story
    For the best viewing experience please update your browser to Google Chrome