Running lights not working

[Roberth]

Here’s a question for guys who know trailer wiring issues. The running lights on my trailer stopped working. I replaced the truck socket and the 7 way plug on the trailer. Still not working. Tester shows power to the appropriate slot on the socket and when I put power to the slots on the trailer plug from a battery the lights work but not when plugged into the truck. Any ideas as to what’s wrong.

 

[onefish]

check the ground

 

[Rayvon]

I had the same issues last year,turned out to be just corrosion/dirty pin connector.Get a bit of fine sandpaper/emery cloth and clean every slot out.Or the ground.

 

[Damn Ugly]

Instead of running your ground through the frame, run dedicated ground wires from the connector all the way back to the lights. In addition to eliminating bad circuits, I think its helping to reduce overall corrosion as well.

 

[Roberth]

I had the same issues last year,turned out to be just corrosion/dirty pin connector.Get a bit of fine sandpaper/emery cloth and clean every slot out.Or the ground.

I replaced both the plug and the socket. Didn’t fix it. The turn signals and brake lights work just not the running lights and taillights

 

[fish brain]

Take the ground off the trailer and re do it. Make sure the metal is all shiny on the trailer and bolt. Cut the wire back and put on a new eye.
If anything is not right with your trailer wiring. Nine times out of ten it's a ground issue

 

[Roberth]

If the ground was bad wouldn’t no lights at all work. In this case the turn signals and brake lights are working. Only the running lights and taillights are affected

 

[pacemaker]

Tail lights and running lights run off the same filament on regular incandescent lights. Maybe something as simple as the bulb itself is gibbled…..If it’s not ground or LED lights, it’s this. If it’s not this, it’s ground.

 

[fish brain]

If the ground was bad wouldn’t no lights at all work. In this case the turn signals and brake lights are working. Only the running lights and taillights are affected

If there is no ground they wont work. If the ground is corroded, they won't work properly. have you ever seen trailer lights dim when you apply the brake? Or when using the turn signal, the brake is applied and the both lights flash? A bad ground can do these things and more even though the lights "work"

 

[Foxsea]

If there is no ground they wont work. If the ground is corroded, they won't work properly. have you ever seen trailer lights dim when you apply the brake? Or when using the turn signal, the brake is applied and the both lights flash? A bad ground can do these things and more even though the lights "work"

Bad grounds are a common issue. Also, any wire splice is suspect. I have had problems with butt connectors corroding inside the splice. Damn Ugly suggested a dedicated ground wire, not the frame. I agree. The long term fix is to redo all wiring with tinned, marine wire, LED's and heat-shrink connectors.

 

[sly_karma]

Instead of running your ground through the frame, run dedicated ground wires from the connector all the way back to the lights. In addition to eliminating bad circuits, I think its helping to reduce overall corrosion as well.

I did this several years ago. Has been solidly reliable ever since. Bad ground accounts for a big majority of low voltage electrical problems.

 

[Whole in the Water]

The other alternative is to mount your trailer lights in a 2x4 board and hang them off the back of the boat. They never touch water and always work. I did this years ago after always fussing with trailer lights - never looked back.

 

[sly_karma]

The other alternative is to mount your trailer lights in a 2x4 board and hang them off the back of the boat. They never touch water and always work. I did this years ago after always fussing with trailer lights - never looked back.

With sealed LED lights, the problem now isn't the lights themselves going into the water, it's corrosion in the butt splices and screw ground connections.

So there are two ways to solve the problem, both require re-wiring the trailer. Full circuit home runs, or mount everything on a board as described above. Do it right and you'll never worry about lights again.

 

[scott craven]

I've never found a trailer light that can resist salt water forever.
Get the 'life time' LED lights from crappy tire and when they're done return for warranty replacement.
On my third set.

 

[Roberth]

Thanks for everyone’s advice. I rewired the trailer