Myersrover

I have just fitted a hks turbotimer to my 99 impreza turbo uk it all works fine but now I have to wait to arm my alarm system until the engine cuts out. Can anybody please assist me on how to bypass this? I have read on a website you can snip a wire on the keyless entry module in the drivers side above thefuse box and snip a wire under the centre console but this was all on a 02 USA model... On mine it's all completely different