New alternator and some adjustment to one of the wires cured the problem. The connection on the end had been changed so that it didn't fit in the plug properly and therefore wasn't even touching the tab on the alternator. Maybe fixing this first would have cured the problem but I am happier now it has the correct unit on, belt tension adjustment is much better as the old one protruded too far out. Makes it easier to get the engine side panel back on. Onwards to the next problem now.
Hi Mark,
Detalis from LOCOSTBUILDERS.CO.UK
These tightening values are for standard bolts in a us focus svt, the engine is identical to the st170 lump.
Main bearing cap bolts
Stage 1: 25 Nm
Stage 2: 60 degrees
Connecting rod bearing cap bolts
Stage 1: 35 Nm
Stage 2: 90 degrees