Brake light issue stumping me...

[mmoose68]

OK so I have a small trailer for my boat and have replaced the wiring twice now.

When the trailer is connected, one of the brake lights on my TRUCK do not work. Does that automatically point to an issue with the wiring on the truck side? Where do I start?

 

[MH Hawker]

first off what are you working on a lot of trucks need a adapter was it working and stopped or a new install, did you do it or have it done, my crystal ball is in the shop

 

[mmoose68]

My hitch and wiring was installed by a shop and this is a new install. It is a Ford Ranger.

Thanks!

 

[Scott Danforth]

what year ranger? if the turn signals and stop lights are separate, then there is a diode module that is used for the trailer wiring.

 

[gm280]

what year ranger? if the turn signals and stop lights are separate, then there is a diode module that is used for the trailer wiring.

I agree with Scott. If you have separate bulbs/circuits for the turn signal and stop light setup on the Ranger, and I think it does, you will need a module for the trailer to work properly. And that reason is the brake/turn signal is probably one bulb on the trailer. And without steering and blocking diodes, the feedback to the truck would cause the truck turn and brake to be on/illuminated any time the trailer brake or turn signals were used.

 

[MH Hawker]

i would start by using one of these to confirm its working right on the truck first

 

[MH Hawker]

i would start by using one of these to confirm its working right on the truck first