Well back at it. First thing I needed to go back in and replace the crappy Rockville amplifier. It lost 2 channels and had horrible feedback when swapping source on the radio. I found a Pioneer 5 channel that had good reviews. Its pushing the about the same amount of power and is much smaller. It actually sounds quite a bit better, and i have zero noise when powering up or changing sources on the head-unit.
Then i wanted to add brake lights because we are legal to drive in a local beach town but my cart needed brake lights. I just ordered a $10 brake switch to wire into the factory wiring. I had to fab up a bracket out of aluminum to hold it. That was not hard. I hooked it up, completed the relay wiring behind the dash, and nothing. Turns out because i don't have a turn signal switch that the brake wiring is not complete on a Precedent. Behind the dash I had to make a jumper to go from the signal from the brake switch to both rear lights. I don't have a 9-pin plug so i just made some bullets to shove in there and insulated it with some hot glue. Its a bit crude but it works.
I ordered a cheap timer relay on ebay to time out the brake lights incase i leave the brakes locked and the key on. Its coming from Bulgaria so it might be a while before i get that and install it.