Re: Gearbox earth connection
Reply #2 –
I can also vouch that this will fry an ECU (found out the hard way).
Both Earths originate from the post behind the battery (which is where the battery 0V should be wired to).
Depending on the year,
On early cars, you'll be earthing to the gearbox bracket that goes from the end of the gearbox to the gearbox mount.
On late ones, it goes directly to the one of the top two bolts on the bell housing, you'll see one of the 19mm bolts has a small m8 thread sticking out for this very purpose.
And I can also vouch for mk4 cables too, made starting much quicker!