Try the pink wire on the ignition plug on the steering column. I'm pretty sure that's the normal ignition wire which goes to the coil. The yellow wire is also ignition, but that's only 'live' when the ignition is in the 'start' position, when u turn the key back to 'on' the ignition feed goes through the pink wire I rekon. A test light would be the best way to find out. :thumbsup:
For installing ur alarm/immobiliser, most wires u need will be around the steering column. The fat red wire in the ignition clip is constant 12v, the purple goes to the starter motor (and through the auto safety switch if auto), so that's one immobilisation point u can use, ur ignition as mentioned above, and if u have flasher wires for ur indicators, the indicator loom is also under the steering column....can't remember which ones to splice into, but just use a test light to try all the different wires.