Wiring loom

[Jimbrown]

How much of a task is it to convert the wiring from a 2+1/4 deisel to a 2+1/4 petrol, does it actually need a new harness or is the conversion possible. :?

[muddyweb]

Quite a simple job.. I did it in a day when I was driving my Series 3

You just need to pick up the switched feed from the Diesel loom to power the coil.  

You might need to change the switch barrel, because from memory the diesel switch disconnects the feed you need to use for the coil when cranking.   Failing that, keep the diesel barrel and use a push switch for the starter.