Chasing a trailer wiring gremlin ...

[southkogs]

I need a little direction y'all:

I've rewired my trailer (4 prong, full ground) and had everything working for a day or two. After that - poof - no joy on either tow vehicle.

What's happening: When i plug into the primary TV (just working with one to eliminate variables), the ground wire on the vehicle side is getting warm (the 4 prong plug is getting warm too), the tail lights (markers) dim to about 1/2 their brightness when the trailer is not plugged in and I get no driving / marker lights on the trailer. Trailer brake and signal lights are still working (these are LED lights).

What I've done: I've tapped a new hole in the trailer and grounded the white wire to that new hole. I've disconnected the side marker lights to make sure the path to the rear lights is not interrupted, I've tried with the trailer disconnected from the TV and have run a jumper cable from the boat trailer to the TV frame.

Still no joy ...

I'm kinda' at a loss in direction at this point, and don't know if I should be lookin' harder at the TV or at the trailer.

Any ideas are welcome.

 

[bruceb58]

Get a spare 12V battery and connect it up to your 4 pole harness. You could also use a battery charger.

 

[lckstckn2smknbrls]

If the wiring is getting warm you have a direct short.

 

[GA_Boater]

If the wiring is getting warm you have a direct short.

I respectfully disagree. Shorts blow fuses. Poor connections lead to increased resistance and warm wires.

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Kogs - Do you have a converter for separate turn signals in the primary TV? But that's a separate issue if the lights are funky on the TV with the trailer disconned.

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If the trailer is a tilter, extend the white ground to the trailer frame after the tilt hinge or split the wire and run the white directly to each lights.?

 

[lckstckn2smknbrls]

If the fuse is rated too high it won't blow. The wire will melt.

 

[GA_Boater]

You assume it's over fused, I assume it's fused properly. We have no idea.

 

[southkogs]

Get a spare 12V battery and connect it up to your 4 pole harness. You could also use a battery charger.

Thanks Bruce. I'm a total novice at this, so let me double check on how I did it: took the battery charger, set it on 2A. Grounded to the trailer frame (roughly where my ground wire connects - the ground post on the harness is sheathed) and touched the marker light post on the harness.

... at which point they all lit up like they were supposed to.

If that test needs to be done with the ground post exposed, lemme' know and I'll figure out a way to test that way.

A short in the TV is not out of the question: thanks for mentioning it 'cause I forgot to say this in my original post - I did blow the fuse on the van ('07 E150 / it had/has the correct 20A fuse in it) but I had been putzing with the ground on the trailer and I hit it to the exposed marker light wire on accident. I think that's where I toasted the fuse. I replaced the fuse and lit everything back up with the same result (nuthin' on the trailer and dimmed van lights) and the fuse did not blow after sitting for about 15 minutes or so. I've been guessing at a ground issue on the trailer, but just can't figure out why.

It's not a tilt trailer, so no break. I did have it grounded back at one of the wheel fenders, but a friend here suggested that I move the grounding spot further forward and directly to the frame. And no converter on the van.

I figured if I could localize trailer vs. TV, I'd get down the path quicker.

 

[bruceb58]

So, sounds like your trailer is fine. For one final check I would run the ground of the battery charger through the ground of the connector instead of going to the frame. It's likely going to work fine but just a sanity check.

Do both your brake and/or running lights dim on your van when you add a load?

 

[southkogs]

Do both your brake and/or running lights dim on your van when you add a load?

Good question ... I didn't check the brake lamps to see if they dim. I'll do a check hooking to the ground wire and then check to see if the brake lights dim too. If all goes well, I'll turn my attention to the van side of the equation.

I haven't really cracked that nut open again being a complete novice on wiring. I may just opt to pay someone to put a new tail on it.

I may not get to that tonight, but I'll report back in.

 

[lckstckn2smknbrls]

You assume it's over fused, I assume it's fused properly. We have no idea.

The trailer has LED's, they draw much less amperage.

 

[southkogs]

Didn't get to play with the van tonight, but did get out and work on the trailer. Using the batter charger hooked up strictly to the posts on the wire harness, all the lights work just like they're supposed to. I had two spots where I used a washer and a light wasn't grounding right, but that was easy to find once I had things lighting up. Within about 30 minutes, I had everything re-assembled in full (I had disconnected a few marker lights) and the rig lit up like a Christmas tree.

I'm a little worried about kludging up the van, and it's only about $40 to have the local shop re-wire the harness. So, I'm going to have that done tomorrow night and hopefully that'll complete the odyssey.

Thanks for the push guys.

 

[GA_Boater]

Did you plug into the van, Kogs?

 

[southkogs]

Did you plug into the van, Kogs?

No. I didn't get to look at the van or pull the boat out of the garage - it was pouring here this evening. As I said above it's possible that the van does have a short in it. I've actually done nothing different to the trailer (except unhook and re-hook a couple lights) since when I started. So, I'm thinking the gremlin is over in the van.

I have never really pulled much at night before with the van, but we've started cruising in the evenings a little during the week so trailer lights were more of a concern. (Here in TN, as long as your vehicle lights can be seen during the day ... you're legal even if the trailer doesn't light at all) The trailer worked behind my truck at first, but then after hooking it to the van it stopped working behind either. That's when I started messing with wires.

I'm figuring there is a good chance that the van had/has a wiring problem and that just kicked my other problems into play. Either way - a new harness isn't gonna' hurt the van (it's probably due for one anyway) and it's not too expensive to have someone do it.

Now ... if it doesn't all work right tomorrow night ...

 

[southkogs]

Well, I had the van harness re-done. They goofed on my appointment and the Admiral had to take it over. She couldn't remember exactly what the dude told her, but she's sure he didn't use the word 'short'. Anyway, new harness on the van ... and the trailer works just fine now.

I hooked everything up tonight and tested it all out. We'll dunk it this weekend and see if all my connections hold after getting wet.

Thanks again guys. Bruce, that trick with the charger really helped (and I never would have thought of it).

 

[bruceb58]

Glad you got it fixed. Battery charger is just a poor man's power supply and perfect for something like this.

 

[GA_Boater]

Good, Kogs. :thumb::thumb::eagerness::eagerness::wave: