Trailer light frustration

Hello all. Hoping to find something here I can’t on my own. 2018 Tacoma trd sport, 45k miles, went to buy a utility trailer recently and hooked on to leave(in the rain), went to plug in the lights(older lady was unsure if they worked) and saw an arc at the plug when I did. Lights were a no go. Replaced 4 prong plug, entire harness and lights on the trailer, double checked ground, plugged in, no lights at all. Checked fuses in the fuse box under the hood, as well as in the box under the steering wheel. Can’t find a single blown fuse anywhere. Connections are still good no corrosion anywhere. Am I missing something? At my wits end.

 

My guess is the trailer has a wiring screwup somewhere in it. It sounds like you’re dealing with a trailer that the owner is unsure of so I’d take it to a trailer shop and let them sort it out. You’ll spend a little, but save a lot of headaches. Throwing a arch makes me blame the trailer as the issue unless you have electrical mods, then I guess it could be either.

 

Do you have the white ground attached to the metal frame of the trailer?

 

I do have it grounded at the front near the hitch. Cleaned the metal and used a new brass bolt/washer/nut to be sure. Could I have fried anything besides a fuse somewhere? Like I say the trailer harness, lights and plug are all brand new.

 

Get a multimeter and check your trucks plug..if its all good you know the trailer has a wiring issue. My trailers wiring was heinous underneath it when i bought it.

 

Do you have another trailer with known working lights to see if the issue is at the truck or trailer ? Narrow that down first and foremost, use a tester at the trucks plugin if you don't have another trailer. Once you isolate that then start working your way back to source. If it's in the truck a wiring diagram will help trace it.

 

you should find a trailer plug tester at any auto parts store. They are relatively cheap and plug into your trucks trailer receptacle. The lights in the tester should let you know if the truck circuit is functioning properly.

 

As @GlitterGulch said, a cheap multimeter would answer a lot of questions.

 

Get a trailer plug tester at any auto parts store or RV/boat dealer.

 

There are a couple fuses to look for. Don't just look at them though, test them with a multimeter.

Then the trailer, it must have a short.
This is a basic wiring diagram... it shows a ground to chassis. You can also have a floating ground where the ground goes directly to the lamps.