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Who knew a bad ground strap could cause so many problems!

 
Old 05-06-2010, 02:26 AM
  #16  
Mongo
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For some reason my battery ground strap in my hatch has white paste on it. I seriously hope that is not JB Weld holding the wingnut onto the stud.
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Old 05-06-2010, 02:29 AM
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Originally Posted by Mongo View Post
For some reason my battery ground strap in my hatch has white paste on it. I seriously hope that is not JB Weld holding the wingnut onto the stud.

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Old 05-06-2010, 02:31 AM
  #18  
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Originally Posted by dr bob View Post
If I were looking for a ground strap for the engine, I'd be looking at welding cable with crimped lugs and maybe lined shrink sleeves over the crimps. Welding cable is a lot more tolerant of vibration than most jumper cable materials, and it comes with relatively hi-temp insulation. A welding supply store will make the cables for you usually. Also-- you can buy 1ga battery cables in lug-to-lug configurations in many places that will also do the job. If you can get it at a marine store, they use tinned copper in the cables so less chnce of internal corrosion. As much as I love the original braided/open weave ground cables, there are better choices these days.
Excellent ideas.

I'm expecting the insulation on the new cable I installed to already be cooked off from the exhaust.
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Old 05-06-2010, 03:00 AM
  #19  
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Originally Posted by Maleficio View Post
Yup... I know what I am also doing this weekend... ground cleaning again.
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Old 05-06-2010, 04:53 AM
  #20  
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Originally Posted by Mongo View Post
Yup... I know what I am also doing this weekend... ground cleaning again.

I'm gonna forego the cleaning and move right into replacement.
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Old 05-06-2010, 05:21 AM
  #21  
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You know whenever I'm under the car on that side, I think it would be nice to replace that engine ground cable (have no electrical issues, but I try to take a PM approach).

At the bigger car shows here there are always one or two electrical specialist stands, who have a big selection of ground cables. So far I've never remembered to take the strap off in time for me to be able to take it with me and match to suitable replacement.

Having read this thread I'm going to try harder to make sure I have it with me at next event where they'll be on sale (probably the big indoor classics show at end of the year).
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Old 05-06-2010, 09:41 AM
  #22  
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I personally witnessed a bad ground strap (battery to chassis). It looked clean, with a shiney end and ground point. All it tool was a little wiggle and the car's digital clock would go out - oh and the engine wouldn't start. Ohm'd out the strap and found the crimp connection between the braid and the end was bad. Took it off and bangged on it with a hammer. It was better, but the owner decided that was not a good permanent fix and got himself a new ground strap.

I think it's time maybe I treat myself to a new ground strap. Mine could be original, who knows. Keep the old one as a spare.
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Old 05-06-2010, 11:02 AM
  #23  
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What is the part number for the negative ground strap to the battery?

EDIT: Nevermind I found it. Part is 928 612 009 13.

Last edited by Mongo; 05-06-2010 at 11:18 AM.
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Old 05-06-2010, 02:23 PM
  #24  
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The Pelican thread had a ref to a great tape.

Originally Posted by MPDano View Post
... Also, I was thinking maybe adding a heat resistent layer to the ground near the engine. I use the Vulcanizing Silicone Tape in high heat areas. I used it on my Harness when I rebuilt it.

Good stuff:
Moroso 72038 - Moroso Self-Vulcanizing Tape - Overview - SummitRacing.com


You could use that, @ $26 for 12'. After all, speed costs money, how fast ... ?

Or you could go with 6 10' rolls of the same stuff @ $30:
Repair tape ľ X-treme Tape - Duluth Trading Company

Or 1-1/2" x 10' @ $8.50:
Repair tape ľ X-Treme Tape - Duluth Trading Company

Or 36' @ $20:
36 ft Roll E-Treme Tape - Duluth Trading Company

It's amazing stuff any way you cut it.
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Old 05-06-2010, 03:28 PM
  #25  
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Originally Posted by Maleficio View Post
I changed out the main engine ground strap today on my '82.

It fixed my cylinder misfire and overall imbalanced running problem. Engine is very balanced and harmonized now.
Oh, I knew that.

You don't have to change the strap. Add another wire, as heavy as you've got, between the body and the engine. It won't fry with power, Ohm's law is still in effect, it will lower the resistance and provide a clean ground without "fun" impedance effects from the corrosion.
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Old 05-07-2010, 12:03 AM
  #26  
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If you are looking for battery and ground cables custom made, try this guy:
http://www.custombatterycables.com/index.htm
I bought some custom cables from him and was very happy with the product. Very well made to my spec. I think his shop is not taking orders right now but should be in the near future. I have no connection with him, just a satisfied customer.
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Old 05-08-2010, 12:31 AM
  #27  
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Originally Posted by GlenL View Post
Oh, I knew that.

You don't have to change the strap. Add another wire, as heavy as you've got, between the body and the engine. It won't fry with power, Ohm's law is still in effect, it will lower the resistance and provide a clean ground without "fun" impedance effects from the corrosion.

So you're saying it's less hassle to install another ground cable somewhere else than it is to change out the bad one and replace with a good one?

Too late, I've already replaced the bad one, and it paid off nicely.
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Old 04-24-2016, 03:15 PM
  #28  
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Default Part # for the Main Engine ground cable?

Can someone post the part number for the main engine ground cable? I need the one mentioned in many posts, but I cant seem to find anyone listing the part number. And I have tried to find it in the parts stores, but always seem to get the one on the top of the engine, not the bottom.

I need the part number for the one on the bottom, passenger side. Mine looks original and is filthy. I am hoping replacing this might help my idle, no start issues.
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Old 04-24-2016, 03:16 PM
  #29  
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Default Sorry, forgot model and year

Sorry....forgot I have two Porsches...This is for my 1982 Porsche 928S(manual).
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Old 04-24-2016, 03:17 PM
  #30  
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Originally Posted by PorscheTX928
Sorry....forgot I have two Porsches...This is for my 1982 Porsche 928S(manual).
Roger @928sRus has everything you will need for your 928. Except gas.
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