What is the reason for the harness for the 03+ Silverado taillights? When I get the lights, do I pull the old harness for the stock lights?

 

The 03+ have four lights while the 99-02 only have three. You will replace the old harness with the new harness that comes with the 03+.

 

Thanks

 

OK another question...I don't see many auctions up for lights with the harness included. How hard would it be for me to modify my harness to accept the 4th light? Obv I'd have to get the sockets and bulbs, if possible, but if I remember right the 4th light on the side does the exact same thing as the dim filament on the brake light bulb. So...could I just tap into the wire for the dim filament?

 

Here is a nice right up on how to convert your existing harness to the 03+ harness.

convert 99-02 harness to 03+ harness

 

Exactly what I was looking for. Thank you.

 

No problem.