p100 engine swop from 1.8 td to a 2litre dohc help help

[sierrap100]

o.k i started this project thinking to would not be to hard how wrong i woz i have lots of questions if any one will answer you would be helping me to not give up a dream and on cars altogether.i have the doner sierra dohc with all wiring taken of the engine but i want to have electric windows,mirrors, i know i cant use the old p100 diesel loom so i have started taking out the dohc loom its a in nitemare i mean it.i cant seem to be able to seperate the engine loom from the cars interior loom which heard it woz just a case of disconnecting plugs now i relize that is not the case as far as i can see.i have the relay box unbolted.trying to fit engine plugs through a small grommit hole i havent tried yet id say wont work either.will i have to rewire the whole p100 with the dohc wiring loom will the rear lite connections fit the rear lite connections of the p100 etc and is the an easier way am i going about this all wrong help realy realy apreciated

[dickkark]

use all of the car loom as it will all be there for you to just refit in the p100
treat it as if you were just swapping it from one car to another,this may mean removing the entire dash but its not that bad a job.
if you start joining bits of loom it will end up a mess and you could run into other problems like different fuse boxes between diesel and petrol/fuse and relays will differ.and every thing is ready to plug in if you swap it over,no fussing just mark everything up with tape.
the rear lights will be the easy bit.
as all cars have basically the same lighting arrangements i.e.
side/stop/indicators/fog and reversing lights.
the wiring is probably coloured the same anyhow.