Might be of help to someone searching in the future, been looking at a mk2 Focus (1.6 VCT sigma engine) that was recovered in non-start.
Initial diagnostic check had codes for primary circuits A & B on ignition coil, circuit faults on both intake & exhaust VCT solenoids.
Checked feeds to coil pack and VCT solenoids, no voltage on key on.
Checked wiring diagram and coil pack, injectors and VCT have feed from fuse 34 in battery junction box (underbonnet fuse box) checked 10a fuse blown.
Obviously dead short to ground on the green/white wire that feeds these components.
Didn't blow fuse straight away though, drove car for about 15 mins without an issue then it blew fuse the next time it was started!
Checked loom and eventually found chafing on the loom near block connector, that's near the starter motor, the insulation was rubbed through and could see where green/white wire had arced against one of the starter motor bolts.
Repaired wire and fault is solved.
Thought I'd mention it on here in case anyone's searching in future.