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Earth cable alternator to body

Posted: Sat Aug 16, 2025 9:42 pm
by leedurrant73
Hello,
Where can I buy an earth cable that fits to alternator to body?

Cannot find one?

Thanks


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Re: Earth cable alternator to body

Posted: Sat Aug 16, 2025 11:51 pm
by Nine One One

Re: Earth cable alternator to body

Posted: Sat Aug 16, 2025 11:53 pm
by leedurrant73
Thank you.

I did see this but was thinking it wouldn’t be right considering it’s for 78 onwards. But I guess it would work.

Thanks Lee


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Re: Earth cable alternator to body

Posted: Sun Aug 17, 2025 8:01 pm
by leedurrant73
Hello,

Here are three important ground straps I’m replacing. I’ve replaced the battery grounds straps. Are there any other important ground straps I need to replace?

Is there another under the battery box area on passenger side of RHD car?

Ground Strap Gearbox. Porsche 911 / 964 / 993
CODE: 99961192020/1

Alternator to body ground strap
CODE: 91161223300

Porsche/ Kroon Ground Strap Engine Fuse Panel (91161200800)

Thanks Lee


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Re: Earth cable alternator to body

Posted: Mon Aug 18, 2025 5:44 pm
by RobFrost
I think there are straps on my 1970 car from the outsides of the battery boxes to the wings, for the benefit of the horns and lights.

Then there is definitely one attaches the rear deck lid. It spans the left hand hinge if I remember correctly, and has a black vinyl sheath around it.

Finally I assume there is one on the bonnet but I can't remember what what one's like.

There may have been some earths among the rear quarter light cables - thinner ones in a brown sleeve. I can't remember for sure.

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Re: Earth cable alternator to body

Posted: Mon Aug 18, 2025 9:37 pm
by SeanP
Alternator to engine is a 914 part number
engine to body earth strap
earth strap for each battery
Multiple earths in the wiring looms
Front trunk light goes to the switch
Rear number plate lights go to a stud in the left hand engine bay
Rear lights earths go to the bumper mounts
Loads of earths in the front trunk
Many earths under the dash

And they are all grounds not earths!

Re: Earth cable alternator to body

Posted: Mon Aug 18, 2025 10:48 pm
by leedurrant73
Thanks Rob, Sean.

I’m working it :)


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Re: Earth cable alternator to body

Posted: Wed Aug 20, 2025 12:06 pm
by leedurrant73
Hello guys.
The funny thing is some of these grounding straps were missing before I started the restoration. I have an occasional starting issue when turning the key nothing happened. Lights went dull etc. makes me wonder if the car actually had an earth grounding problem?

Glad I’m replacing all :)


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Re: Earth cable alternator to body

Posted: Wed Aug 20, 2025 4:31 pm
by SeanP
You have to make sure that all the grounding points are clean and making a good contact with the metal underneath. especially with the motor to body and battery ground straps.

I did have an issue where the path to ground was through the gear change and it melted all of the bushes in the gear change mechanisms!

Re: Earth cable alternator to body

Posted: Wed Aug 20, 2025 4:37 pm
by leedurrant73
God damn. Better do some checks thanks Sean


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Re: Earth cable alternator to body

Posted: Wed Aug 20, 2025 4:46 pm
by leedurrant73
Hey Sean

I recently attached my brown earth wires from my light boxes at the rear. I’m wondering if I should have removed some paint the where they bolt on the bumper area.

Is that what you did?

Thanks Lee


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Re: Earth cable alternator to body

Posted: Thu Aug 21, 2025 8:22 am
by SeanP
It all depends on if you want the lights to work!

Did you clean the threads before you installed the bolts?
Did you use a clean unpainted washer and bolt?

I ran a tap through the insert in the body to remove ant paint and dirt, used a new clean bolt with a new flat and spring washers and sandwiched the terminal ring between the washers.

I also have upgraded all of the rear light bulbs to LED’s to reduce the electrical load on the systems, ( I have upgraded almost every bulb to LED within the car for this very reason. The only lights that I have not converted is the alternator idiot light and the headlights as they are H1’s and I am still on the lookout for a decent conversion bulb).

Regards

Sean

Earth cable alternator to body

Posted: Thu Aug 21, 2025 9:07 am
by leedurrant73
Hey thanks buddy

Yes I replaced with all new bolts washers etc so I’m hoping it will be ok.

Maybe I should do the same with bulbs. Do you happen to have a list of bulbs you used.

Don’t worry if you don’t, just an idea.

Thanks Lee


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Re: Earth cable alternator to body

Posted: Thu Aug 21, 2025 11:37 pm
by leedurrant73
Has anyone got a few pics of alternator grounding strap to body. Looks like I cannot find one?

Thanks


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Re: Earth cable alternator to body

Posted: Fri Aug 22, 2025 5:48 am
by sladey
Ok this is from my later car - 1987 - but it earths to a bolt through the hole with the swarf coming out of it. I stripped the bolt when tightening it up and had to drop the engine to drill it out and replace it

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