alright i picked up a 2000 si spoiler and hooked it up everything worked lights came on when i hit the break closed the trunk cleaned shop up got in it to check and make sure it still works and when i hit the brake no brake lights light up only when i turn my running lights on. i have an automatic and usually when you push the brake in it releases the shifter so you can put it in drive well its not releasing i cannot figure out whats wrong someone please help. i need this fixed ASAP.

 

The brake light fuse is probably blown. Check your wiring for shorts to ground. Also if you're saying the spoiler lights up when you turn the running lights on, the interaction between the running lights is either because of improper wiring (spoiler light "ground" connected to the running lights instead of ground) or a faulty ground in the trunk. The wires between the trunk lid and the rest of the car tend to break where they flex every time the trunk is opened.

 

well what about it not releasing the shifter?

 

That's because there's no power from the fuse. You'll probably also find the horn doesn't work now; same fuse. The fuse is in the underhood fuse box.