MORE Trailer/Truck issues...post dealer visit...(see last post by me starting the same)

[Labswine]

So, I went to the dealership to get my 7 pin connector checked out because the trailer dealership thought that the issue was potentially with one of the truck control modules.

Well the Jeep dealership tested everything, both the flat 4 and the 7 pin connector and didn't find anything wrong even though the trailer dealer's tester showed that the running light circuit was active not only when the truck was not running but with the brake controller disconnected.

So, I go straight from the Jeep place to pick up my trailer. Get it all hitched up and go to test the lights. Initially nothing. So, I pulled the 7 pin plug out, and put it back in firmly. That's when I saw the lights on my brake controller show connection. So far so good...or so I thought.

Testing lights, I put on the LEFT turn signal on the truck, walk around to the back of the trailer and the RIGHT turn signal is flashing ? ? ?

Walk back around to the truck and turn off the turn signal and the truck. I went back to the rear to look at the 7 pin again and noticed a dripping underneath. Pulled the plug and looked underneath the truck and the connection from the wiring to the plug itself WAS ON FIRE ??? I was able to simply blow it out...

So, looking at the wiring harness from the truck to the 7 pin connector, I noticed that a lot of the wiring cover was kinda rough looking and wires were exposed and looking like they heated up and melted the wiring insulation at least 2 feet back from the plug itself.

So, anyone have ANY clues or pearls of wisdom I can impart to the Jeep dealership when I take my truck back in on Monday?

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[K1w1t1m]

You need to find wiring diagrams for the 7 pin plug. The trailer running lights will have nothing to do with the brake controller.
I do know there are two ways to wire a 7 pin connector, one is for travel trailers, the other is for utility trailers.
It is probably best that you learn all you need to know so you can fix it as taking it to the dealer or the trailer place only nets finger pointing at the other party.

 

[jeepers29]

Is the trailer tow wiring stock? If so, then the dealer needs to fix the issue. If it is not, they will tell you to talk to whoever installed it.

 

[Labswine]

Is the trailer tow wiring stock? If so, then the dealer needs to fix the issue. If it is not, they will tell you to talk to whoever installed it.

The trailer wiring harness is factory.

You need to find wiring diagrams for the 7 pin plug. The trailer running lights will have nothing to do with the brake controller.
I do know there are two ways to wire a 7 pin connector, one is for travel trailers, the other is for utility trailers.
It is probably best that you learn all you need to know so you can fix it as taking it to the dealer or the trailer place only nets finger pointing at the other party.

I am not an electrician so that's outta my skill set.

The factory harness and plugs were tested by the dealership (both the flat 4, which is for utility trailers and the 7 pin for travel trailers with electronic brakes) and tested fine...at least there.

The trailer dealership hooked up the trailer to a box they have that simulates a tow vehicle and everything worked normally...turn signals, brake lights, running lights.

They also have a box they can plug into the 7 pin and it'll show the various functions that the tow vehicle will exhibit.

When they hooked it up last week, it showed that the running light circuit was active even with the truck turned off. The dealership also did this and didn't see any issues.

I hook up my trailer and turn signal lights blink the opposite of the expected input (right on the trailer with left selected on the truck) and it was that that started the little fire at where the wiring harness connects to the 7 pin.

Additionally, looking at the wiring harness, there's about two feet worth of the insulation/wrapping that looks melted and wires are exposed. Seems this has been going on for a while.

Last time I towed was last September and there were zero issues. Why now, after a year since the last tow? Something's a little screwey...and nothing was touched in the interim...it just happened all by it's lonesome ? ? ?

 

[Jaxmax]

Steven the wiring harness melted and burned and shorted connection , that's why circuits were acting funny, the Jeep Harness is shorted and has to be replaced...But something caused excessive current to go through the wiring, you've towed a lot already so everything was fine at one point, something shorted such as the battery charge circuit to running light wiring, a loose connection will cause the burning and fire. The jeep harness and connector are shot and have to be fixed, then be sure the wiring on jeep is fixed and correct, before plugging in your trailer. Disconnect your trailer battery before any testing as a failed battery could be a problem also. Who ever looks into the jeep harness should be able to trace the fault back to the source, any good electrician can.....Jack

Ps: West Chester ain't far , just catch that escaped prisoner and maybe I'll swung by if you are stuck.

 

[Labswine]

Steven the wiring harness melted and burned and shorted connection , that's why circuits were acting funny, the Jeep Harness is shorted and has to be replaced...But something caused excessive current to go through the wiring, you've towed a lot already so everything was fine at one point, something shorted such as the battery charge circuit to running light wiring, a loose connection will cause the burning and fire. The jeep harness and connector are shot and have to be fixed, then be sure the wiring on jeep is fixed and correct, before plugging in your trailer. Disconnect your trailer battery before any testing as a failed battery could be a problem also. Who ever looks into the jeep harness should be able to trace the fault back to the source, any good electrician can.....Jack

Ps: West Chester ain't far , just catch that escaped prisoner and maybe I'll swung by if you are stuck.

The trailer battery is working just fine as it's still got the juice to raise and lower the tongue jack.

Yeah, I am going to pitch a fit that the dealership (Jeep one) only did the tester thingy...plug in a simulator and see what's going on but NEVER looked underneath at the wiring itself because the harness has melted and wires are exposed. I'm bringing that up as a bone of contention to reduce the cost of the repairs plus, I am going to point out that it's a safety hazard because it the wiring has melted this badly (after a year since I last towed) then it could happen at any time to restart a fire.

My warranty is up because of time not mileage...I've only got like 27,6xx miles on it but it's over 4 years old now.

Yeah, I hope they catch that clown soon. I'm about 8-9 miles from where he was last spotted but I can still hear helicopters flying over in their search.

 

[Labswine]

Bump...

The dealership now has my Gladiator. They gave me a RAM 1500 for a loaner whilst they work on the Jeep.

Anyone with an electrical background have any clues that I might be able to impart to the dealership to aid in their search for the issue? @ShadowsPapa seems to be an electrical guru...any pearls of wisdom you can give me to impart to the dealership?

One thing I did say to the service manager was that in order for the wiring casing to melt, exposing wires, and the silly thing catching fire, was that SOMETHING is putting way too much voltage through the trailer electrical harness which is causing it to heat up and causing some cross circuiting like the right trailer turn signal to blink when the left one is selected, and blinking, on the truck, in addition to the trailer running light circuit being constantly 'hot' when the vehicle is not even running (also still hot when the headlight switch is turned to 'off' instead of 'auto' and the vehicle not running).

It only went in yesterday (9/11) so I haven't heard anything yet as to what's going on.

 

[ShadowsPapa]

Well the Jeep dealership tested everything, both the flat 4 and the 7 pin connector and didn't find anything wrong even though the trailer dealer's tester showed that the running light circuit was active not only when the truck was not running but with the brake controller disconnected.

That part is pretty easy to take a shot at - perhaps even explain:
You drove it from A to B.
At one point, the wires were touching where they should not.
At the other point, they were not.
Not sure in which order things happened, but if it showed ok at the dealer then you drove it to the trailer place, things moved and touched.
If the trailer place was first, then things moved and were no longer touching.
Intermittent is what I'd call it at that point. A disaster in the making, waiting for something to move or shift or get hot again.....

There's a lot of things that could cause it - rodent damage comes to mind. I had to spend a whole day and then some replacing huge sections of the wiring under a nice newer camper I had years ago. I mean in some spots there was no insulation at all, in other spots only tooth marks, and in one spot a section of wire was missing, just plain gone (I hope the copper poisoned the little #@$%@ or punctured their intestines but I couldn't be so lucky)

Also - trailers have a battery to activate the trailer brakes in case of a disconnect. That little cable that runs from a box up to your tow vehicle - if the hitch comes un-hitched, that wire is pulled and there's just enough power in a battery in that box to activate the brakes and slow or stop the trailer. (if you did a good job that will never happen because the crossed safety chains would prevent that, and your locking the hitch on the ball would prevent the safety chains from ever being needed)
I've always wondered - what would happen if something went bad in that emergency braking box on the trailer - could that battery system ever short?
There's always up to 30 amps to the trailer connector and the trailer brake circuit can handle up to 30 amps back there - so you then have two hot wires to the trailer when sitting with the brake pedal pushed down.
If either of those was chewed or damaged and contacted, say, the ground, it could heat up the other wires in the harness and then you get a lot of crossing over.

Anyway - this is a sticky situation as there's only three possibilities as I see it from here, not seeing the actual harnesses and not having the trailer by my shop for deeper testing, and you will not like the 3rd at all:

A. Truck harness was physically damaged - rodents, rocks, ice pulling, etc.
B. Issue with trailer - emergency brake device shorted, or anything else on that same connector pin/hot wire drawing too much load (which should really kill the fuse but that doesn't always happen as I've seen in my observations)
C. Connector inserted incorrectly.
Some say that's impossible, can't happen - and yet I have found two instances of that exact thing happening. A quick - oops, that's wrong, turn it over, insert it correctly, but it was enough to heat wires, melt and merge insulation and do some damage.
I've experimented and most connectors are way too tight to even do that a little, but some trailer connectors are just a loose enough fit they can be flipped and just make contact - not be plugged in, but the contacts actually do touch inside during that brief moment.

The Jeep dealer is going to blame the trailer - and it makes sense since there's really little about the truck harness that can actually "self-destruct" without outside influence (rodents, rocks, bad trailer wiring, etc.)
A trailer connector and harness left on it's own will last forever. So I can't really blame the dealership if they charge for all repairs. There's nothing about that harness, left by itself, that can cause a problem, without outside influence. Those wires run next to each other, but there's no way in that sleeve for them to make any contact. Ain't gonna happen. Even at the socket - the wires are so far apart, spaced, something else has to trigger the issue.
And that's either trailer or user.

Here's the positioning of the high amp constant hot wire compared to the ground - 180 degrees off. And look at how far out the contacts in the socket stick! Doesn't have to be fully inserted to actually touch the pins in the truck connector.........

And for the non-believers -

And here's a picture from a guy who actually had this same thing happen to him -

Just saying - open mind, there's not really anything the truck itself has or does that can cause burned trailer wiring. It MUST be either the trailer has a problem, outside influence like rodents or rocks or ice, or user error. And it happens............

 

[Labswine]

@ShadowsPapa I'll buy the 'rodent' issue but, they went over everything on the trailer when I had it in for inspection, after I told them about the issue of the running lights coming on when plugged in to the truck and everything turned off, on the truck, and just the one side of the brakes locked up. They said all was right with the world in that respect, everything tested out just fine on my trailer.

I am well aware of people trying to put the plug in 'upside down' and am VERY cognizant of how I've inserted the plug from the trailer into the 7 pin on my truck because I really don't wanna pay to have any stupidity on my part repaired.

When they (the trailer dealership) tested my vehicle with their plug in tester, the only thing it showed, out of the ordinary (even with the brake controller unplugged) was that the trailer running light circuit was hot with every thing off, and even with the headlight switch set to off instead of 'auto'. Everything on the trailer tested fine.

As far as the 'emergency' brake line on the trailer, if it were that, then why would only one side lock up and not both sides, unless there's an internal problem with it itself ? The line itself has never been yanked on so I cannot see that being the issue.

It'll be interesting to see the result as my dealership called and asked if my trailer was still at the trailer dealership (about 4 miles from the Jeep dealership) because the tech working on my truck wants to go there and test my trailer. I was told that quite a number of the techs at the Jeep place also have Gladiators and tow with them and have never encountered this issue which is why he wants to work with the techs at the trailer place to see what's going on, potentially, with my trailer too.

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