924Board.org

Blas · Joined: 05 Nov 2002 Posts: 227 Location: Illinois, USA

This weekend I will be inspecting all the grounding points on my 1979 - 924 as I have noticed a slight fluxation in my instrument gauges.
I know there is a ground lug under the hood, at the front drivers side (USA) near the headlight. Another in the rear at the tail lights. (I forget which side) and of course the original heavy cable coming direclly from the battery along with the dealer added second cable at the battery.
Where would the grounding locations for the interior dash etc. be located.
Should I be concerned with the possible "crispyness" of the wire due to age? Has anyone run a wire directly from the battery ground to the interior grounding spot (where ever it is?) and pigtailed it on to the original grounding point?
Any other grounding points I should inspect?
Like the windows, mirrors, etc.
Thanks for any help...
Blas

D Hook · Joined: 02 Nov 2002 Posts: 3158 Location: Omaha, NE

Way up under the dash there's a grounding ring. You almost have to remove the black box under the steering column to get good access to it. Also cleaning the connections into the black box will help. (Heck, cleaning ANY connections will help.) Then use dilectic (sp?) grease when reconnecting to keep the corrosion at bay. In the back hatch there's one on the driver's side wheel well near the courtesy light behind the carpet, IIRC, besides the one you've mentioned. Then the ones that connect to the instruments, too. Especially the large round one that connects to the temp/fuel guage.

CMXXXI · Joined: 05 Nov 2002 Posts: 1939 Location: Vicksburg, MS

Here's photos of all the ground points. I've got one more that I still need to photograph - from the bell housing to a bolt securing left control arm.

(Click photo for full photo gallery)
_________________
'79 Eurospec 931

Smoothie · Posted: Wed Sep 29, 2004 8:12 am Post subject: Re: Grounding Location Points

The Fife · Joined: 17 Mar 2004 Posts: 241 Location: San Antonio, Texas

I found the above three grounds on my 924S and:

- one from the battery cable to the firewall, right near where the battery is. Can't miss it, this one is less than 6 inches away from the battery.

- on the engine block above the flywheel inspection hole. Cover the hole before taking the bolt off or you might lose it. The battery cable and something else grounds there.

- Behind the starter. Not a ground, but the battery cable or something plugs in there, and it's kind of exposed to the elements.

- The rail in front of the oil pan / under the front of the engine. This was a single wire, not a very big one and secured with a Phillips screw.

- Behind the glove box. I think some of the gauge lighting grounds there.

- I couldn't find the ground for the instrument panel... do I have to remove the black box to see it? It's a 924S in case it's wired differently from the 924.

Not a ground, but on my car it needed some attention: The two connectors to the sensor mounted on the top, rearward, drivers side of the radiator. I noticed it while doing the ground near the drivers side headlight.You might want to have a look at those two wires and the connection. It could be a temp gauge or something else.

Blas · Joined: 05 Nov 2002 Posts: 227 Location: Illinois, USA

WOW...the most comprehensive answer I have ever seen or received...The Photos are fantastic (you must have been waiting for someone to ask for help on this topic...and BAM ! - you got 'um) ....will definately speed up this weekends project work. But I wonder if you can really access the big cluster under the dash with big hands?
Thanks all...

Chrenan · Joined: 15 Jan 2003 Posts: 3903 Location: Canada

If you want to access the grounding points under the dash, it is easiest to remove the driver's seat. Then, you can lie on your back with your lower legs and feet resting on the rear seats, and your head under the dash. Makes it easier and it is only a matter of taking off 4 10mm bolts that hold the seat in.
_________________
1987 951 - M193 Version for Japan

CMXXXI · Joined: 05 Nov 2002 Posts: 1939 Location: Vicksburg, MS

I made photos of the ground points because this seems to be one of the most frequently asked questions. I hope you find them helpful.

Getting to the grounds above the fuse box is definately the hardest one. As Joe points out, you have to lay on your back in the footwell. Do yourself a favor, take your Dremmel tool with you when you crawl down there. Remove each grounded wire, then use a small grinding bit to lightly clean both sides of each of the prongs on the crowns. After they are clean, apply some dielectric grease, lightbulb grease or a thin coat of vaseline to each one and reattach the ground wires. Once you get down there, you'll agree that you only want to do this operation one time, so do a good job of it the first time.
_________________
'79 Eurospec 931

Chrenan · Joined: 15 Jan 2003 Posts: 3903 Location: Canada

Do people mistake me for Joe because I have a yellow 924 or because my posts are hard to understand?
_________________
1987 951 - M193 Version for Japan

CMXXXI · Joined: 05 Nov 2002 Posts: 1939 Location: Vicksburg, MS

Oops

my sincerest, most humble apologies. Yes, I saw the yellow car in the avitar and didn't stop to think that the grammar and sentence structure were in a different league.

...won't happen again... <skulking away in shame>
_________________
'79 Eurospec 931

Chrenan · Joined: 15 Jan 2003 Posts: 3903 Location: Canada

That's OK! Just joking around anyway, I am secure in my ability to type using correct grammer. Keep the good information coming CMXXXI, you've solved a few of my 924 problems over the last couple of years.
_________________
1987 951 - M193 Version for Japan

Khal · Posted: Thu Sep 30, 2004 8:18 am Post subject:

Hey! Your batteries are on the wrong side!

And I'm pretty sure that's not ALL the ground points in CMXXXI's photo's. Not to knock the photo's mate, they are brilliant. Several grounds I didn't know existed. But I'm pretty sure there's more, at least on ROW cars...
_________________
'80 924 Turbo

tj924 · Posted: Thu Sep 30, 2004 9:10 am Post subject:

I found the grounding point in the rear on the LHS wheel arch under the carpet but there is nothing attached to it & I couldn't see any loose wires sitting around waiting to be connected. Is that normal?

When reattaching the ground points, am I to understand that a small amount of vasoline or something should be applied to each connector? Once the whole lot is back together, should it be covered by a "blob" of the stuff or does that just leave a mess?
_________________
TJ
Silver '82 924 NA 5-Speed Manual

Lizard · Posted: Thu Sep 30, 2004 12:09 pm Post subject:

Smoothie · Posted: Thu Sep 30, 2004 1:25 pm Post subject:

Dielectric grease is non-conducting. It has to be used (if grease is called for) on multi-pin connectors where you don't want to create a path for current between connectors. For ground points that aren't close to any other connections, no need to go buy special stuff - you can use vaseline or whatever. One thing I wouldn't recommend though is paint because it can seep into connections by capillary action, dry in there and end up blocking the current flow. When I bought my car, it had battery problems caused by some paint the PO had sprayed on the battery connections.

As Sleykin'd tell ya, Nolox paste is conductive and anti-oxidizing, making it good for battery posts and ground points. I suspect it may be silver-based and expensive though.

Globs - no globs needed, just enough to coat the metal and inhibit oxidation.
_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox