Trailer lights go out once the coupler contacts the hitch/ball?

[jmo]

Hi Guys,

so when the trailer is plugged in but not hitched, all lights work. The moment the coupler contacts the ball/hitch all of the lights go out! I don’t see any shorts, but there is definitely corrosion on the various ground points for the lights. What is interesting is if it’s hitched, and I turn off the “running lights” on the truck, my brake and turn signals work? Any ideas?

thanks

[NautiqueJeff]

Definitely a ground issue somewhere.

[bturner]

Sounds like you have the answer, now you just need to find the culprit. To me it sounds like you have a short in your running light circuit.If you have a folding tongue that is the first place to start looking.

[jmo]

Thanks - I do have a folding tongue, but visual inspection hasn’t revealed any compromised wires, the white (ground) wire from the harness is screwed into the frame, so it seems it is grounded even without the hitch contacting the coupler. I don’t get why they all work when it’s not hitched but I lose everything once it is?

[shag]

If you have the original wiring on the 2006, I would just re-wire the trailer. It isn't that expensive and probably like others said, a short somewhere is crossing things up. Sometimes just the wire riding around in the frame for a period of time can short wires across each other... Just my .02

[jmo]

Thanks - the trailer was bought new in 2012, but yes I might need to rewire it. The next puzzle is now after driving it home 160 miles everything is now working again, which is almost worse as now I can’t as easily troubleshoot it!

Update: spoke too soon, backing up in reverse seems to give life temporarily, once I unhitched and rehitched the problem resumes.

[bturner]

Start with cleaning and reattaching your ground on your trailer. This could be a ground potential issue that is occurring.

[jmo]

Thanks everyone - problem solved. Turns out it was a loss of continuity between the swing tongue and the main trailer frame. I cleaned up a bunch of the grounds, which didn’t help. But - the white ground wire from the 5 pin connector is screwed into the swinging tongue and relies on continuity to pass through the hinge to the rest of the frame. It was combination of a missing the bottom washer where the swing tongue pin inserts, which when you then lower the coupler onto the hitch it twists just enough under the weight to lose connectivity, that and the hinge side bolt & washers were really rusty so I cleaned that up as well!

that was nuts…

[shag]

Great! Glad to hear you got it working. That is a problem area sometimes for sure.