I bought a harness for it from ebay over in the US rather than tapping into the existing wires, but think things may be a bit awry with it, considering the timer isn't working (only turns on briefly then straight off if I scratch the earth wire agianst the earth point - once secured it stays off)
Having investigated the harness, there are a couple of wire sthat have been cut, presumably when they installed the alarm (before I had it).
What I have at the moment is two wires going to a permanent 12v live, neither of which lose voltage when starting the engine, and both go up to 14v (or thereabouts) when the engine is running. I have found what I believe is the ignition wire, giving 0.45v when off and c. 13v when ignition is on, no voltage drop when engine is turned over. I have another two wires which show no voltage but which seem to go straight to earth.
Can anyone tell me which wires need to go where, as it's somewhat puzzling. Haven't tarced the wires that have been cut yet, so may have something to do with them too I guess.