I have an older jensen all i did was ground out the parking switch wire but my boy guy a newer model jensen and had to put the wire on a toggle switch. Some of the stereos have to be able to tell a switch occured so that it will turn on.
well running the e-brake wire to the ground kinda worked LOL. what my home boy told me to do is hold the pink wire on a ground for 2 seconds and let off for two more seconds and then hold back to the ground and it will come on then he told me. to cut ground that end then come in and cut the wire in half and run a switch to it. and so there for thats what i did and it works just great.