My mate told me he would Fit a new stater motor.

We have no info on this but wiresinstalled incorrectly I doubt would fry the ecu but you never know, get them hooked up right then try to start car. Thee shold be alarge fuse that blows to protect circutiry so check underhood fuse box.

Welllike I said we have no info n vauxhalls we dont' h ave them in the u.S. But anyhow have your battery checked. It should read 12.4 volts at least with engine off then have it load tested. Clean the terminals if it tests ok then check your starter relay and fuse it should be in your under hood fuse box. If it still won't startthe check your cablesbut you shold know a lot by the time you test what i've said. It cold be possible it's an ignition switch as well. One other thing don't let your mate touch your carunless you are giving him a ride lol.

Check yoru battery first and your relay and fuses. It may nto be your switch and pro should check that anyhow.