Just finishing up work on the engine and want to ensure things are grounded properly. I took one ground wire off when removing the head and I think it went from the head to the car frame but I'm not sure I remember that properly. Where should the engine/transmission grounds be located? And what gauge wires should I use? From what I've read I think I need...
- one from the transmission lower bell housing inspection cover bolt to the car frame
- one from the engine block to the car frame
- one from the engine head maybe to the engine block or the car frame

I've heard if you don't ground the engine/transmission properly you may have issues with, for instance, the clutch cable being the ground which isn't good!

If anyone has any pictures of where their grounds are located it would be great if you could post just to ensure I locate them correctly.

Here is some info:

There is a heavy ground wire from the chassis to one of 4 bolts that attach the flywheel inspection plate. I can't find a spec for the gage wire, but I would eye ball it as slightly less than that of the Neg battery ground.

This pic shows the ground for the wire that bolts to the back plate on the exhaust cam housing. About 10 to 14 gage.:


The next pic show the 2 grounds for the FI wiring harness:


I don't remember any other engine grounds but once mine goes back together, I may re-discover others

I found this "extra" ground cable at my previous job, and made a good home for it!

wizard124 wrote:Here is some info:

There is a heavy ground wire from the chassis to one of 4 bolts that attach the flywheel inspection plate. I can't find a spec for the gage wire, but I would eye ball it as slightly less than that of the Neg battery ground.

This pic shows the ground for the wire that bolts to the back plate on the exhaust cam housing. About 10 to 14 gage.:


The next pic show the 2 grounds for the FI wiring harness:


I don't remember any other engine grounds but once mine goes back together, I may re-discover others

Anyone know what gauge the ground wire should be (if replacing)?

Along with all of the factory ground wires that wizard124 has shown, I added one when I installed Mark's 95-amp alternator.
I used a braided strap I got on-line, and attached it between the alternator belt-tension adjustment bolt and the inner fender well.
It is overkill, but I'd rather be safe than sorry.
When I first bought my car, it left me stranded 2 times because of charging problems.
Hence the bigger alternator and additional ground strap.:

In the import tuning scene it was common to use 8gauge wire as follows:

Alternator > Chassis
Intake Manifold > Chassis
Block > Chassis
Battery > Chassis


Doing this, you could reliably MAKE real hp from ~$15 of materials. You will DEFINITELY see a change in voltage on your battery when grounded well... and all the benefits this creates.

Wow. Great pics and info once again. Thanks everyone.

Car almost ready for spring. And I will have piece of mind driving it knowing that I've dealt with all the issues I could think of. I wanted to fully rebuild the front suspension as well but I think that can wait until next year. Components seemed fine and I ran through the suspension checks mentioned on the Fiat Spider suspension guide.

Funny that the PO told me that everything was fine on the car and I could just drive it. I guess 'fine' is a relative term.