Wiring problem traced to tow vehicle but more confused now- look what I found

[mike64]

So a boat I recently bought had a right turn light not working. The guy said he swore he fixed the light, and it was working on his vehicle. It worked a little but was really dim. I figured it was a ground problem and I'd just rewire the whole trailer. The right light wasn't working at all when I tried it again today. But the trailer wiring tested fine for continuity. I didn't think it would be the wiring in my Jeep because I had a problem last year so I installed a new wiring harness in the Jeep, and it's been working great. And I tested the LED lights on my other boat trailer today, and they worked fine on my Jeep.

But troubleshooting confirmed it was a problem on the Jeep, at least with traditional incandescent lights, so I tore open the back panel where the trailer wiring is jacked into my Jeep, and here's what I found:

Obviously a short or something caused some serious heat buildup in that converter thingy. So a few questions:
1. could it just be that these wiing harnesses go bad and just replace it?
2. Or do I have something wrong with the wiring in my Jeep I need to worry about? All the lights on my Jeep work fine.
3. Or could a crappy wiring job on the boat I just bought have caused this? Because it's been working fine, both on my old boat (LED lights) and my utility trailer (traditional incandescent bulbs) ever since I replaced the Jeep wiring harness last year.

 

[burp]

Re: Wiring problem traced to tow vehicle but more confused now- look what I found

I'd suspect a trailer wiring problem caused the converter problem on your Jeep. With the bubbled appearance, I'd be surprised if it wasn't caused by an excessive current draw (short or mis-wiring) on the trailer.

 

[Snowfish]

Re: Wiring problem traced to tow vehicle but more confused now- look what I found

Sometimes those converters just go bad. Why? If you haven't blown any fuses, just plain magic!:facepalm: Not saying that there's not an issue with your new to you boat. But since you have separate trailering fuse, on your Jeep (left, right, & running), I vote for magic.

You do know that you have separate fuses, right? Are any blown? Or is you set up aftermarket?

 

[mike64]

Re: Wiring problem traced to tow vehicle but more confused now- look what I found

You do know that you have separate fuses, right? Are any blown? Or is you set up aftermarket?

Snowfish, yes, it is an aftermarket wiring harness. It's the second one- I had one installed for me at a trailer place years ago, and I replaced it when I had a problem with it last year (it was a problem with the left light then).

Burp- I suspect you're right with a problem being in the trailer wiring, because when I drove it home after I bought it my digital odometer and radio readouts were doing strange things- blinking when I put a turn signal on, and shutting off when I used the brake. This only happened the one time I drove the boat home.

 

[H20Rat]

Re: Wiring problem traced to tow vehicle but more confused now- look what I found

Burp- I suspect you're right with a problem being in the trailer wiring, because when I drove it home after I bought it my digital odometer and radio readouts were doing strange things- blinking when I put a turn signal on, and shutting off when I used the brake. This only happened the one time I drove the boat home.

100% dead short somewhere in your trailer, which may have cooked the adapter.

 

[sw33ttooth]

Re: Wiring problem traced to tow vehicle but more confused now- look what I found

usually it blows my fuse and then i got no lights or speedo till i get a new fuse happend a few times like a 15 amp fuse, i put a 15 blew, then i put a 20 in and it blew so i put a 25 in and it blew then i put a 5 in hasnt blown yet. dont ask me the differnces this is why electrical items are not returnable after you buy them they have a 1 what ever chance that it wont work and it was bad from factory. trailer wiring can suck diagosing but then again thats half of what i get paid to fix