Trailer hitch/lighting issue

[hoamskilet]

Had a weird issue pop up tonight on my snowmobile trailer. I replaced the 7 pin plug/cord on my trailer the other night. Drove it home from the shop at work where I did the work and everything worked great. I since then ordered this hitch:

Went to hook up tonight and none of the lights work. At no point of pulling the plug in and out did they even flicker. Tested the plug on the truck from the ground pin to the running light pin just to see if I had voltage there, and I did. Out of frustration, I put my old hitch back in that looks like this:

All of a sudden everything works with no issue. Makes no sense. The only thing I can come up with is when I replaced the trailer cord, I ran it into a junction box where I terminated everything with ring terminals. There was an existing ground wire at that location that is screwed to the frame....the only thing I did with it was put a ring terminal on the end of it and then connect it to the ground wire coming back from the plug into the juncion box. Maybe where it's attached to the frame it's not getting a good connection and with the old hitch it's getting more of a ground to the truck since the ball is actually welded and part of the hitch as opposed to the adjustable hitch which is connected with pins. Thoughts?

 

[01yellercobra]

I'd say you're onto something with the ground. I had a similar issue with my car trailer. The lights would flicker while driving. Pushing on the hitch would cause the lights to flicker. I happened to touch the emergency brake cable and it was hot. I did some searching and found the ground on the trailer side was broken. I fixed it and all is good again.

 

[1wild-horse]

It's grounding through the ball. Check the ground in the trailer plug.

 

[hoamskilet]

It's all fixed. The spot where the ground wire attached to the frame under the trailer was bad.

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[beau t]

It's all fixed. The spot where the ground wire attached to the frame under the trailer was bad.

Sent from my SM-G975U using Tapatalk

Good find and thanks for posting, i have the same thing happen with my swing away boat trailer but its only a issue backing up the hill in my driveway, its grounded on the swing side and looses ground when the trailer crest the hill and unloads weight from the swing portion but it took me a minute to figure it out lol.