I just finished installing type s tail lights on my 04 base TL. Everything was working well, i stop off at a meet and my friend is like you have a tail light out. So i check and sure enough it was out. When my lights are on the tail light does not light up, it only lights up when i press the brakes. I searched the other forums and didnt find any problems quite like this so sorry if it is a re-post. I think that the problem is the wire from the LED board to the connector....any idea's what this problem can be?

 

it's the wire to the led board like you said. you probably have to re-install it making sure that the male and female connections are tight or check to see if a connector needs to be replaced if that doesn't work.