Need Help: Lights not working when Flat Towing

[cinap]

Hoping someone can tell me if I'm doing something wrong or what my issue might be. I ordered my JL in 2019 and had the RV/Flat Tow wiring harness included as part of my order (Mopar Part# 82216358AA). I hadn't used it until now but, long story short, something isn't working. The turn signals, brake lights, etc. do not seem to function when connected to the motorhome.

I've tested the circuit on the motorhome connection, which is working fine.
I've tested the connection cable that runs between the motorhome and the Jeep, which also works fine.
Finally, I used an external power source (12v battery) to test the harness inside the Jeep by connecting leads between the 12v battery and the ground & turn signal pins on the harness. This didn't work.

Anyone run into this before? Any ideas what I might be missing? I don't believe there are any settings I need to change in the system menus and, as far as I know, it should work with the Jeep turned off anyway.

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[garyji]

Not familiar with that harness. Is it fused? Sorry, I know that wasn't much help

G.

 

[cinap]

Not familiar with that harness. Is it fused? Sorry, I know that wasn't much help

G.

Yes, it has four 10A automotive mini fuses. All seem to be in good working order.

 

[Rhinebeck01]

Yes, it has four 10A automotive mini fuses. All seem to be in good working order.

@cinap

"Seem" and are in fact in good working order may be two different things.

IF, if you do not have a tester, at the least swap, out all 4, 10amp fuses and then see if that remedies the issue.

 

[cinap]

@cinap

"Seem" and are in fact in good working order may be two different things.

IF, if you do not have a tester, at the least swap, out all 4, 10amp fuses and then see if that remedies the issue.

I took out all four and did a continuity test with my multimeter...all of them are good.

 

[Rhinebeck01]

@cinap

Perhaps at this link you can get some ideas... help...
https://www.jlwranglerforums.com/forum/threads/battery-charging-with-mopar-flat-tow-harness.70565/

Ask guys in that thread about their install and for their assistance.

 

[Rhinebeck01]

@cinap

Here is your remedy!
https://www.jlwranglerforums.com/forum/threads/mopar-flat-tow-harness-arrived.20833/post-651083

 

[cinap]

@cinap

Here is your remedy!
https://www.jlwranglerforums.com/forum/threads/mopar-flat-tow-harness-arrived.20833/post-651083

Dang, I was hoping you were right, but mine is a 4 door and both grounds are connected...the search continues.

 

[Down South]

It seems several others have had problems with this harness. To be honest I know nothing about the factory toad/towing harness. I used an aftermarket harness that I had to splice in at the tail, marker and brake lights.
I'm assuming the factory tow harness has diodes. I wonder if they are wired in correctly? Meaning the correct direction.

I've read where others were having a power problem to the harness? I'm not sure what requires 12V power on this harness, a control box maybe?
The harness I use is powered from the motorhome as far as lights, tail, marker and brake/turn signal.
I have a charge wire from the motorhome to the Jeep battery. My toad brake system is powered from the Jeep battery is the reason for my charge wire.

I'd do as mentioned above and have a look at the links offered. Plus there is a sub forum dealing with towing that you could post this problem in that might get more attention and better advice since it's related to towing.
Towing, Trailering, Flat-Tow

 

[FWB FL]

It seems several others have had problems with this harness. To be honest I know nothing about the factory toad/towing harness. I used an aftermarket harness that I had to splice in at the tail, marker and brake lights.
I'm assuming the factory tow harness has diodes. I wonder if they are wired in correctly? Meaning the correct direction.

I've read where others were having a power problem to the harness? I'm not sure what requires 12V power on this harness, a control box maybe?
The harness I use is powered from the motorhome as far as lights, tail, marker and brake/turn signal.
I have a charge wire from the motorhome to the Jeep battery. My toad brake system is powered from the Jeep battery is the reason for my charge wire.

I'd do as mentioned above and have a look at the links offered. Plus there is a sub forum dealing with towing that you could post this problem in that might get more attention and better advice since it's related to towing.
Towing, Trailering, Flat-Tow

What I did also works great

 

[cinap]

Update...from what I can tell, it looks like the dealer installed the fuse box incorrectly. The colored wires with the white stripe are in the correct locations, but the matching solid color wires are not aligned to their striped siblings. Now I just gotta figure out how to get them out of the housing without damaging them, lol.

 

[Rhinebeck01]

Update...from what I can tell, it looks like the dealer installed the fuse box incorrectly. The colored wires with the white stripe are in the correct locations, but the matching solid color wires are not aligned to their striped siblings. Now I just gotta figure out how to get them out of the housing without damaging them, lol.

@cinap

Pinned connector probably... you will need a re-pinning tool and have a clue how to use tool to release. Not that hard to do but...

Consider going to your local Automotive AM/FM/Stereo install/repair place/store and have them to the deed for you. It will be a an easy thing for them to do and cost you little... as they will do quickly.

Better then you damaging the connector... and getting angst doing the deed... 8-)

 

[Bilymac]

Take it back to the dealer and have them install it correctly this time.

Update...from what I can tell, it looks like the dealer installed the fuse box incorrectly. The colored wires with the white stripe are in the correct locations, but the matching solid color wires are not aligned to their striped siblings. Now I just gotta figure out how to get them out of the housing without damaging them, lol.

 

[Down South]

He has probably figured it out by now.

Updates would be nice though.

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