SL-Class (R129) 1990-2002: SL 280, SL 300, SL 320, SL 500, SL 600, SL 60 AMG

SL/R129: R129 Electrical / starting issue

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Feb 13, 2018 | 06:10 PM
  #1  
Tinhorse34's Avatar
Thread Starter
Newbie
 
Joined: Jul 2017
Posts: 2
Likes: 0
1992 500SL Class R129
R129 Electrical / starting issue

I have a 1992 R129 500SL that at times will not start. When you turn the key the dash lights up and it seems like I am getting power but nothing happens. Sometimes it will start and run smoothly but when you turn it off......It may not start again for hours or even days. When it does not start it makes no sound what so ever, it just won't start. At first I thought it may be the starter solenoid or something mechanical but after checking fuses and anything else I or my local mechanic could think of we finally determined it was an electrical issue but could not pin point the culprit. The only clue we have is that when this problem happens my power antenna and sometimes my climate control stop working too. The nearest MB dealer is approx. 85 miles away and just getting it there is another problem in itself. Any ideas when to start looking for this electrical gremlin or any ideas or suggestions at all would be a great help.
Reply
Old Feb 15, 2018 | 03:57 AM
  #2  
Tinhorse34's Avatar
Thread Starter
Newbie
 
Joined: Jul 2017
Posts: 2
Likes: 0
1992 500SL Class R129
Ref: Posting the Vin

Sorry I should have posted this info in the first submission.
It is a 1992 500SL and the Vin # is: WDBFA66E7NF041340
Reply
Old Apr 24, 2018 | 04:56 PM
  #3  
Russell Ormerod's Avatar
MBWorld Fanatic!
 
Joined: Jun 2011
Posts: 1,494
Likes: 131
From: Cape town
not a merc
Test term 50 output from your ign switch and renew electrical part!
Reply
Old May 16, 2018 | 10:32 AM
  #4  
Nabil Ammache's Avatar
Newbie
 
Joined: May 2018
Posts: 4
Likes: 0
500 SL 1992
Originally Posted by Tinhorse34
I have a 1992 R129 500SL that at times will not start. When you turn the key the dash lights up and it seems like I am getting power but nothing happens. Sometimes it will start and run smoothly but when you turn it off......It may not start again for hours or even days. When it does not start it makes no sound what so ever, it just won't start. At first I thought it may be the starter solenoid or something mechanical but after checking fuses and anything else I or my local mechanic could think of we finally determined it was an electrical issue but could not pin point the culprit. The only clue we have is that when this problem happens my power antenna and sometimes my climate control stop working too. The nearest MB dealer is approx. 85 miles away and just getting it there is another problem in itself. Any ideas when to start looking for this electrical gremlin or any ideas or suggestions at all would be a great help.
Hello
i do have the same problem in my 500sl 1992 , did u find the solution ?
Reply
Old May 16, 2018 | 10:34 AM
  #5  
Nabil Ammache's Avatar
Newbie
 
Joined: May 2018
Posts: 4
Likes: 0
500 SL 1992
hello

i do have the same problem on my 500sl 1992 , did you fix it ? if yes can you help please tnx
Reply
Old May 18, 2018 | 08:40 AM
  #6  
bobterry99's Avatar
Banned
 
Joined: Jan 2006
Posts: 1,982
Likes: 393
From: Atlanta, unfortunately
'09 S600, (2) R129 300SLs, '03 SL500, '03 SL55
On an early 129 the starter circuit is simple: battery > ignition switch > starter switch (automatic transmission, picture) > starter solenoid.

Reply
Old May 18, 2018 | 01:18 PM
  #7  
Nabil Ammache's Avatar
Newbie
 
Joined: May 2018
Posts: 4
Likes: 0
500 SL 1992
Originally Posted by bobterry99
On an early 129 the starter circuit is simple: battery > ignition switch > starter switch (automatic transmission, picture) > starter solenoid.

tnx a lot , i already bought a new ignition switch since last year i had a problem with the key stuck in it i did repair the lock , so i am gone change the ignition swich then i will check this part near the gear box !! I will post the result when its done ! I really appreciate your reply , i do visit a lot of MB repair garages and none of them knew what's going on , i do have my SL since 1997 i never had a major problem with it ! Tnx again
Reply
Old May 18, 2018 | 02:22 PM
  #8  
Nabil Ammache's Avatar
Newbie
 
Joined: May 2018
Posts: 4
Likes: 0
500 SL 1992
[QUOTE=Nabil Ammache;7457189]tnx a lot , i already bought a new ignition switch since last year i had a problem with the key stuck in it i did repair the lock , so i am gone change the ignition swich then i will check this part near the gear box !! I will post the result when its done ! I really appreciate your reply , i do visit a lot of MB repair garages and none of them knew what's going on , i do have my SL since 1997 i never had a major problem with it ! Tnx again[/QUOTE
When i turn the ignition on usually i do hear the noise of the fuel pumps for half a second , mine sometimes the pumps dont works when the ignition is on ! So i checked the fuses box all is fine and i do check the mass module its also working well !! When i had this problem and i didnt hear the pumps working i took off the mass module off and i try a wire between the soks number 2 and 22 nothing happened!! I did also cheked the over voltage fuse and it is fine ! I get under the car near the fuel pump and i test the wires i didnt find any electricity in the wires to the pumps !! The second day i try to turn on the ignition everythings works well !!!! So had this problem so often !! A day the car start fine and another day don t !! When it turn on it doenst stop at all ! Tnx for help
Reply
MB World Stories

The Best of Mercedes & AMG

story-0

New Electric Mercedes-AMG GT 4-Door Coupe Unveiled: 10 Things You Need to Know

 Verdad Gallardo
story-1

6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

 Verdad Gallardo
story-2

Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

 Verdad Gallardo
story-3

Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

 Verdad Gallardo
story-4

8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

 Verdad Gallardo
story-5

Flawlessly Restored Mercedes 190E Evo II Heads to Auction

 Verdad Gallardo
story-6

Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

 Verdad Gallardo
story-7

Mercedes EQS Gets A Major Update: Everything You Need to Know

 Verdad Gallardo
story-8

5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

 Verdad Gallardo
story-9

Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

 Verdad Gallardo

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 10:25 AM.

story-0
New Electric Mercedes-AMG GT 4-Door Coupe Unveiled: 10 Things You Need to Know

Slideshow: Mercedes-AMG's new electric GT 4-Door Coupe trades combustion for software, synthetic noise, and more than 1,100 horsepower.

By Verdad Gallardo | 2026-05-20 20:08:15


VIEW MORE
story-1
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-2
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-3
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-4
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-5
Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-6
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-7
Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-8
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-9
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE