I know I'm commenting on a 15 year old thread but with hope someone will be able to comment... Jeep grand cherokee, trying to fit push button start and its driving me mad. It's all working except the acc wire which i understand is negative trigger and through a resistor so needs a relay, but I cant for the life of me figure it out. When I push the button the car starts but without the acc wire I have no electronics, and although I can still drive the car, abs and airbag lights are on presumably because the cars module isnt getting power. I have installed a lot of alarms, remote starts and other things over the years so far from a novice but this is baffling me. Do I just, via a relay, connect the purple/brown to earth? Or do I also need to put a resistor inline?