Trailer wiring issue

[Jc12]

Hey guys I recently used this plug and play harness for my trailer wiring and have the below issues

Hopkins 43415 Plug-In Simple Wiring Kit for Toyota 4Runner 1996-2002:Amazon:Automotive

Turn signals and brake lights work only when the running lights are off
Once the running lights are on the turn signals blink very faintly and both at the same time like my 4 ways are on

I've installed these before and did everything correctly this time around. I've tested it on different trailers and get the same results. Could it be a bad converter? I ordered it from the states so it's basically cheaper for me to just replace than to mail it back, has anyone experienced this issue? Thanks!

 

[98OzarksRunner]

It sounds like you have a bad ground somewhere.

 

[W Demarco]

If the t4r has no problems with its lights, check the ground at the junction of t4r frame and the ground wire from harness. If that is clean, continuity test from that ground to the ground pin on the trailer side of the harness. If the ground is continuous at that point then clean or redo all of the ground points on the trailer. Sand ground lug, sand ground point, reattach. A single intermittent ground can throw lighting into a tizzy! Often you can find the bad ground by just tightening or even wiggling the interconnection.

 

[csp]

Agreed, it sounds like you have a bad ground and certain lights are backfeeding others because of this.