Trailer Lights dont work when headlights are on.

Hi All,

Interesting problem. I have a 2008 Explorer Limited with factory installed flat 4 wire harness. I installed light kits on hitchalong I have. When the headlights are off, the trailer lights work without any issues. I have brake/turn. As soon as I turn the headlights on (or if lights are on automatic and headlights come on) the trailer lights stop working.

Anyone experience this before? Thanks for the help.

 

[BigRondo]

Maybe a bad ground? Just a thought.

 

[thall8801]

Hi,

Yeah, its first thing I thought too. I checked all the grounds, seem ok. I tried the trailer on my 2002 sport trac, and no problems. The problem seems to be on the 2008 explorer.

Neighbor was thinking maybe something with fuse and the smart junction box....

 

[GreenMando]

Two of the wires are reversed. They have a tester that plugs in that will tell you which is wrong. Could be the 02 or the 08.

 

[thall8801]

Finally broke out the multimeter. See good signals from the explorer. Changed the harness plug on the trailer side, and all is working. Seems like it was makeing bad contact with the 08 explorer, but ok contact with the 02. The harness came with the lights wasnt the best quality. Put on a heavy duty, and good to go.

 

[BigRondo]

Thanks for the update. Glad you got it figured out.