Trailer wiring problem

[dlogvine]

I just got a trailer, tried to check out the wiring, no signal to the lights. Started with the ground wire which goes to the frame, drilled a new hole inserted a bolt and checked out that there is no paint at that spot, tightened the ground wire to the bolt, still no lights. Changed the main harness, no luck. Started checking the continuity. Hooked up the plug to the truck with lights on and disconnected the left wire (brown/yellow) to check out the signal. When I connected the test light to brown wire and directly to the ground wire, it worked. As soon as I touched the ground wire to the trailer, the signal disappeared. Grounded the wire to the brake actuator, worked fine, grounded to the main trailer frame, again no signal. Im kinda lost and quite frustrated. Any help or advice is greatly appreciated. It should be something very simple, but somehow I just cant figure out what could be the problem.
The trailer has 3 side lights on the connected right side and one rear light. Left side is not hooked up yet, used it for testing.
Thank you

 

[alldodge]

Does your other trailer work correctly with the same type connector?

Is the trailer on the ball or just the jack?

 

[gm280]

Trailer ground is never a great idea. However, you need to get this sorted out before doing anything else. Try running a separate ground wire from one of the side lights to the ground on the pigtail connector at the vehicle. And then see if that works. If so, you have wiring issues on the trailer. If that doesn't work, you have a problem with the vehicle wiring. No other possibilities! That is the typical good testing point doing that. JMHO

 

[dlogvine]

Does your other trailer work correctly with the same type connector?

Is the trailer on the ball or just the jack?

Truck wiring and connector work on my other trailers, both with my boat and jet ski trailers. I’ll double check it again, since there could be some fuse problems, happened before. But if I get the power on the test light, connected directly to the harness, that should eliminate the connector issue.

 

[alldodge]

The white should be ground for both truck and trailer
Somehow its a bad ground at least to me

 

[dlogvine]

I finally got it to work. Several issues. First one was in old wiring. Bad ground connection. Second one, that I was really upset with myself was a little adjustment of the adapter in the towing bracket. I went to the storage and tested the output on the other trailer to see that it was not working right. Took a little tweak to get it to work. And then the rest went fine.

 

[poconojoe]

Using the frame as a ground is never a good idea in my opinion. I always run a ground from the front trailer connector to the back of the trailer and tap the ground for each light off of that. Always use weatherproof butt connectors.

 

[dingbat]

Thru bolting a ground connection never works for long if at all. At a minimum drill and tap the connection and use stainless hardware and star washers to complete the connection.

Continuity (resistance) between a "good" ground and the connector that plugs into the truck should be 0 ohm, but up to 1 ohm will suffice.

 

[gm280]

You can use the trailers for your ground. However you have to back that ground up with a dedicated ground from each light as well to the trailer connection to the vehicle. That way you have two grounds and make the iffy ground syndrome even less likely to cause issue when you least expect it. A trailer ground only is asking for problems when you are out on the road and need everything to work perfectly... Less likely to get a ticket as well for lights not working!