OK silly question - suffering from lack of memory cells!! Just putting the engine and gearbox back in my Sonett and have completely forgotten where to connect the earth lead which comes from the boot mounted battery all the way through the bulkhead across underneath the engine and ends up near the LH engine mount. As long as it's mounted onto the engine I suppose it's OK but I can't think where it was originally - starter mounting bolts - bell housing flange - I don't know???
Took pics before I started just to make sure I got the cooling hoses back right but can't see the main lead. Stupid thing is I replaced it shortly after getting the car but that was 29 years ago!!!!
There is no earth lead running from the battery to the engine compartment, the battery's earth is screwed to the chassis in the boot. If you have a lead going all the way to the front it is a home made solution. What I would do is join it with the earth lead coming from the engine on the chassis side half way between the coil and the round, louvred ventilation hole.
LHD 95/95's have an off-side/rear head bolt that is tapped for M6 (or M8?), not sure if that's the same on Sonetts. If the earth lead is connected to a bellhousing bolt on a 96, it's most likely retrofit, also on RHD cars I think? Item 25 in below diagram is aforementioned bolt:
Your absolutely right Borstlap it's not the earth lead at all it's the main live feed directly to the starter motor!! Penny dropped yesterday good job I wasn't dumb enough to connect the battery!!!!!! Sorry definitely a senior moment very embarrassing.