Wiring Harness for engine conversion

[DiddyZook]

I am transplanting a M13 (Dohc 16v mpfi 1300) in to a Sierra (was 13 carby).

The new motor being mpfi etc is much more complex than the original so there is extensive wiring by comparison. I have the engine loom and ECU from the donor vehicle (Jimny), but not the rest of the harness.

My question is;

would I be better off trying to build a new harness utilising the wiring diagrams from the Jimny matched to existing Sierra wiring?

or

should I try to locate a Jimny wiring harness and convert everything on the vehicle to match. This would make future maintenance easier as it will match a workshop manual.

I am interested in which would be easier, better long term and cheaper.

I figure that as the Sierra and Jimny are of very similar dimensions that the harnesses should also be of similar size such that they could be interchangeable.

[chimpboy]

Do you need any of the other wiring? If you have the engine loom and ECU, and if this is sufficient to run the motor, then my feeling is you'd be nuts to embark on wiring the entire rest of the car.

Even if you need to wire in a speed sensor or whatever, I still would only go with what's necessary.

I'm talking generically though, I don't know any specifics about the motor you're using.

[nicbeer]

Work out what u are getting first.

either front cut or motor/ecu and assoc bits.

first strip out anything that is not needed from the loom (auto,electric everything,a/c, etc). then decide from there.

I did this when i put the mpfi vit motor into my sierra. still going with wiring now but doing all the other bits now not the engine side.

i choose not to shorten the wires between the engine and ecu but sometimes a good idea depending on length. (the vit ecu mounts in d/s and i mounted it up on the p/s inside the glovebox.

also afaik to your question, wire up the engine/box to suit the sierra gear. run separate fuse box for the new bits. that way u have two independant circuits to troubleshoot if needed and not one big nest,

[cloughy]

Wire up the engine/box to suit the sierra gear. run separate fuse box for the new bits. that way u have two independant circuits to troubleshoot if needed and not one big nest,