Troubleshooting Trailer Lights Going Out When 2004 Ford Taurus Tail Lights are On

Question:

I followed the instructions for a 4 pin trailer light hookup on to my 2004 Ford Taurus. The problem is that when I step on the brake only when the tail lights are on one trailer brake light will not come on in fact the same tail light on the trailer goes out also. When the tail ligths are off everything works fine. Please Help Thank You Very Much!!

asked by: Jerry A

Expert Reply:

It sounds as if you have a faulty ground connection. This could be the ground connection you installed with the 4-Pole Hardwire Kit, # 18252, or a ground on the trailer. When the tail lights are on the amperage draw is higher and a bad ground connection will appear.

Once you check the ground connection for the wiring kit, check the ground at the coupler on the trailer frame, for each trailer light and where any light brackets attach to the trailer frame. Clean all ground points so there is contact to bare metal and you will eventually find the problem. We have a couple of videos detailing ground wire troubleshooting for you to review, see links.

expert reply by: Bob G