I've spent ages working on a central locking fault and am hoping someone who has access to a proper wiring diagram can help! The Haynes manual wiring diagram I have doesn't include the central locking circuit.

Q1. What is in the circuit, if anything, between the fuse (in engine bay fuse box) and the central locking pump 12V feed

Q2. Should the fuse be "live" with the ignition off? (fuse shared with electric window and aerial)

Q3. Can you confirm that the 12V feed for the pump and the 3 door lock switches is common?

Q4. What is the purpose of the second "door open" plunger switch in the front door's leading shut face (ie in addition to the courtesy light switch).

Symptom for those who like puzzles....
- The pump appears to be ok (it's the 12V feed that is the puzzle)
- No faults on actuators and lock switches
- No air leaks
- There is no 12V feed to the pump or door lock switches UNLESS the ignition is switched on AND either of the 2 front doors is physically open...in which case the central locking works fine!!