Tail Gater Switch

[livingez_123]

Just remember, using clear lights on the rear of your vehicle while traveling down the road is illegal.

 

[SLCHOE]

Schematic of the backup circuit for an 04 Tahoe:

Now let's say you don't want to put that much wire in to the reverse light. That's fine, you can tap into the wire in the dash. It goes to your onstar system and tells the vehicle when it is in reverse. To get to that open up the fuse box on the side of your steering wheel under the A-Column.

That wire is actually a 12V switched feed from the BCM. The PCM and BCM use the PNP (park-neutral switch on trans) state signal to determine when to turn your back-up lights on or not (based on programmed logic). This is why you cannot simply ground out a wire to get the backup lights to come on. If all sensor conditions are met, the BCM outputs 12V from Pin F of the BCM C5 connector to this wire. The data is also passed onto the On-Star unit via a separate Class 2 data bus (as well as all modules on the Class Data Bus) basically saying "ok we're in reverse". This wire specifically doesn't "tell" any module anything. This part of the circuit is solely a voltage output wire to feed power to the reverse lights and the trailer connector, nothing else.

Just wanted to put that out there in the name of correct information. Please don't be offended.

 

[StickerShockPDX]

That's funny, I read through this thread trying to figure what the mod was for... I live where tailgating is outside before a football game.

I did this on my little 1972 BMW 2002 when I was a teenager in the early 90's. Worked like a charm.