Engine main earthing

[lukasdeopalenica]

Where originally the main earthing for the drivetrain was located? In my hpe I can find two connections: between the engine block and the front crossmember (not very thick c.a 6mm2) and between the generator and the engine block (rather thin ca.4mm2). I am not sure if this is enough especially for the engine start up requirements. Haynes says about connection that runs from the battery to the gearbox. The same is seen in the electrical diagram I have. 

[HFStuart]

There is a thick (as thick as main batery cable) cable that runs from the main chassis earth on the battery tray to the gearbox. IIRC it goes under the head of one of bolts holding the rear engine mount to the gearbox.

The two you describe sound a bit like bodges. Neither of my betas has had them but I suppose they could have been standard.

[lukasdeopalenica]

Thanks a lot, this is what I needed.

[JohnFol]

Old thread I know but similar question. My battery -ve has 2 small wires heading into cabin near brake servo. Not sure this is original. 
Also have chunky cable to battery tray where it clamps to another cable that again doesn't look original as the other end goes to clutch cable support and has a modified connector (looks like part was hack sawed off). Also have earth cable to back of transmission but assume body earth is from battery tray

So, I have a good opportunity to sort it out. I'd guess I could do battery direct to transmission to save 1 cable. Assuming transmission gasket is conductive... then cable to body work. Are there any better places than one of the 13mm bolts on the battery tray?

[Nigel]

Hi John,
On my car there's a 8mm stud on the rear battery tray support arm, and from there 2
heavy cables, one to battery and one to gearbox. This I believe is fairly standard.
I intend to install another earth cable from the engine to body at the cambelt end,
but haven't investigated where yet.
I wouldn't be concerned about gaskets as the numerous bolts will carry the earthing.

Nigel

[JohnFol]

Thanks Nigel
Do you also have 2 black wires heading into the cabin?

[Nigel]

John, no, i've not seen anything like that.

As you say, they don't sound original.

[mtulloch]

Thanks Nigel
Do you also have 2 black wires heading into the cabin?

Don't quote me as it's been a while but I think 1 goes to the fusebox for the relays etc & the other runs to behind the instruments.

[JohnFol]

That sounds like a good move even if your recollection is not right. Anything that creates a known-good earth somewhere behind the dash would be a good thing

I found the 8mm stud on the side of battery tray and it does connect to the rear of the transmission. However the strap from my battery goes to the battery tray mounting bolt where it joins a different cable to the bell housing.

New cables are on order!