Trailer Electrical help needed

[bellicose]

I have a small kayak trailer that has been working just fine for the past 2 years. I go to hook it up to my Jeep and test the lights, and now I have a problem. The only light that works is the left side marker. It lights up when I brake or use the left blinker. The right side marker doesn't work, nor do the two tail lights. They don't work for any reason, not brakes or blinkers. To add to the confusion, the left marker also lights up blinking when the right blinker is engaged. I thought it might be the wiring harness, so I have just now finished replacing it, and I have the same problem. Anyone have an idea on what could be wrong?

[martix_agent]

are you able to hook up a different known-working trailer to your vehicle?

[Mr. Hick]

4 pin plugs? blow em out with the air compressor first and if that doesn't solve the issue start chasing ground wires.

[Chuck E Ducky]

Sounds like a short or bad connection did you check the wires on your jeep? Also make sure you’re getting a good connection at the plug. Clean them up with some electrical contact cleaner and cover them in dielectric grease so they don’t corrode.

[bellicose]

Indeed, I checked the jeep first thing. Even bought one of those little 4pin tester tools that are like $4. Jeep was good. Though, I think I just fixed it. I've been puzzling over this for 2 weeks, but the minute I post for help, I figure it out. It was a short of some kind. In true MCB fashion, I took it all apart, cleaned all the connections, use solder instead of wire nut caps, traced every line to termination, and reassembled. I think a connection had gotten loose and maybe ground it self out or crossed with another. It works now, so I'm happy. Thanks guys.

[Daltech]

You can always ask, but you always have to do it the way you did.

[Tarsun2]

do you back this into the water?
does it have LED lights?

[THE SHOOTIST]

DC Crud. DC is very sensitive to corrosion. Wet/Damp connections are always suspect of having "DC Crud". Sometimes, you can put a meter on it and it'll read "Good". The problem isn't the voltage, it's the amperage's ability to flow through the "DC Crud". Dielectric Grease helps, but tends to vanish or break down over time.