Steel Warrior

I'v had my 90 S4 for about 15 years and have had intermittent problems with where the grounding strap meets the the grounding post behind the the cover/toolkit holder. According to my mechanic my grounding post is not stock as it looks like a solid battery post with a hex collar below the post and has a "disconnect" device between the end of the grounding strap and this grounding post. The disconnect device is essentially two brass pieces with one end threaded for a 13 mm bolt (battery ground strap end) and the other end looks like a battery post clamp. There's a large green hand **** about 1-1/2 '' across that you turn to disconnect the ground (seperates the two brass pieces). Why someone wanted this in the first place I don't know. My mechanic says the original grounding posts were threaded to accept the 13 mm bolt at the end of the grounding strap.

Anyhow it was giving me fits again as the post was just a hair loose causing slow starting and other problems. I tightened it best I could with a 22 mm socket and now the hex collar looks like a 12-point (lead doesn't like torque). I also removed the plastic insulator between the two brass pieces. Seems to be OK now but I'd really like to get rid of this setup, anybody know where I can get an original type frame grounding post? Is it taped and threaded to accept the bolt at the end of the grounding strap as my mechanic says? Will it extend down through the rear frame/bumper like this one appears to do? Getting this one out could be a bitch but I think it'll come out. Thanks.

MBMB

Can you send a picture of what you're describing? On my 89 GT there is a flat silver spot where the ground strap bolts down, but it appears to be integral to the frame, not a separate part.

928Myles

I used the green **** to bolt the strap down directly onto the ground point. The thread is M10 if I recall correctly. A lot less complicated that what it sounds like you have. The green knobbed bolt allows for easy / quick disconnect as required.

Myles

Steel Warrior

I guess that's my problem, I'm not sure what its suppose to look like. Where you have that flat silver spot I have a "battery" post that sticks up about 1-1/2 " with a integral 22 mm hex collar to tighten it down. Maybe that post threads into the "flat silver spot" cept I have no flat silver spot? It's all black sheet metal around the post.

rbrtmchl

Here is a picture of the ground mounting point. Yes, it's dirty in the picture, I took the photo before I cleaned it up when I was doing my grounds maintenance.

Maleficio

Scrub away the paint around the hole, down to bare metal.

Steel Warrior

Looks like I just need to unscrew the "post" and get rid of the "disconnect" device. I guess the 22 mm collar was hiding all that, I thought it was one piece that ran all the way through the frame. Someone correct me if I'm wrong as don't want to break something.

928porschemangreg

Put some of this around the connections. It will make the contact no longer corrode. Battery post also.

http://www.permatex.com/products/aut...ubricant_b.htm

MBMB

No, I think you're right.

Alan

Something like this: with a battery ground post mount on the ground point? Obviously it isn't stock

You could get a new tighter one or replace it with
or replace it with a battery switch

or eliminate it all together and go back to just a hex bolt.

Alan