Author Topic: Engine ground strap  (Read 2057 times)

MarkCan

  • Full Member
  • Silver
  • ****
  • Canada, Ontario, Mississauga
  • Posts: 261
Engine ground strap
« on: June 20, 2021, 17:00:03 »
I came across an interesting thread on the subject here;
https://www.sl113.org/forums/index.php?topic=26689.0
One thing though, it ended without a definite conclusion. There are options/ possibilities.
After examining the shrouding area I couldn’t find any remains of the other end of the ground cable in my engine bay. I’m leaning towards the short connection and factory grounding location. With the above in mind I decided to attach the other end of the cable  to the coil post. I picked up gauge 4 18inch cable in my local parts place.
I hope this will improve the electrical flow greatly.

Pawel66

  • Full Member
  • Platinum
  • ******
  • Poland, Mazowieckie, Konstancin-Jeziorna
  • Posts: 5492
Re: Engine ground strap
« Reply #1 on: June 20, 2021, 17:21:40 »
Mark, the ground strap between engine block and radiator, fit to the block in the place shown on your picture, is only a part of radio interference suppression. So it came in the car only of the interference suppression kit was there. The main ground cable from the engine goes to firewall.
Pawel

280SL 1970 automatic 180G Silver
W128 220SE
W121 190SL
G-class

MarkCan

  • Full Member
  • Silver
  • ****
  • Canada, Ontario, Mississauga
  • Posts: 261
Re: Engine ground strap
« Reply #2 on: June 20, 2021, 18:32:54 »
Mark, The main ground cable from the engine goes to firewall.
Thank you for your input. I’ll be changing the main ground to as it looks to be battle tested. As a matter of the fact I got the positive cable on order as well. The one going from the battery to the starter. It should be here tomorrow.
Pawel would you be able to post a pic of the attachment point by the radiator?

Pawel66

  • Full Member
  • Platinum
  • ******
  • Poland, Mazowieckie, Konstancin-Jeziorna
  • Posts: 5492
Re: Engine ground strap
« Reply #3 on: June 20, 2021, 19:19:41 »
Mark, sorry, I do not have any good picture. I am enclosing both ends, but the radiator end is not really seen...

Should you need pictures on positive wire routing or source for proper brackets with black rubber, please so advise.
Pawel

280SL 1970 automatic 180G Silver
W128 220SE
W121 190SL
G-class

mrfatboy

  • Associate Member
  • Platinum
  • ******
  • USA, CA, Rancho Santa Fe
  • Posts: 1339
    • Mrfatboy
Re: Engine ground strap
« Reply #4 on: June 20, 2021, 22:16:47 »
This photo might help.
1969 280sl (Aug 1968 build)
Signal Red
4 Speed

MarkCan

  • Full Member
  • Silver
  • ****
  • Canada, Ontario, Mississauga
  • Posts: 261
Re: Engine ground strap
« Reply #5 on: June 22, 2021, 12:53:02 »
Thanks guys,
This has become a great exercise. I eliminated more if’s type connection and found another vacuum leak in the process. Engine running much better now and already quite stable by the sound of it. Definitely on the rich side. It got dark last night so I stopped before I got the actual numbers.
I think it’s time to start with the linkage tour and all the rest of the goodies offered by the site here.