when my trailer is hooked up to my 2003 Sub the trailer lights are dim. Supposedly they were ok when hooked up to another truck so is it possible that I need a heavy duty relay. If so, does anyone have a recommendation on what to get?

 

Check grounds 1st - #1 cause of dim running lights

 

As rednucleus said, check the grounds.


If the truck lights are not dim also, then its a trailer connection/ ground issue.


Heavy duty flashers don't usually fix dim lights, they fix flashing rate issues due to the load of the trailer lights added to the truck lights.


Typically the ground is connected at the trailer A-frame as soon as it's picked up from the truck (through the connector). Ground is the only conductor NOT carried throughout the trailer by a wire, but counts on the frame to be the conductor.


If ALL the trailer lights are dim, then it is most likely the master ground connection at the A-frame area. It could also be the ground pin in the connector (either side).


If only some are dim, then the individual grounds at the lights are the problem.


Steve

 

Lights work now. I believe it was a ground. I bought a new shank and ball when I bought the trailer. I don't think that the shank had enough wear to make a good ground. After driving a bit and having the trailer hooked up a few time every thing works.

 

Thanks for the update, will help others in the future!