Mopar wiring harness to flat tow 2020JLUR behind RV only works for about 15 min

[dalebingham]

The lights and brakes (Roadmaster Invisibrake) work fine when first hooked up to my RV; about 15 min later, only part of the lights work. Harness installed by Jeep dealer (his first install) Invisibrake installed by Roadmaster dealer. Any thoughts? I've read the forum comments about "flashing" the Jeep computer. I'll see Monday if he did that. Thanks for your thoughts. My first time posting and I appreciate all the comments other questions have received.

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[Terminex]

Definitely want to hear what “flashing” is being mentioned.

i have been flat towing mine behind my RV for a year with the mopar flat tow harness, and have never flashed anything.

only issue i encountered at the beginning was due to user error when i installed it.

i do not think the instructions are ver clear when you are connecting the wiring for the front bumper connector. I initially connected a couple wires wrong as it was not clear which end of the connector you are viewing when it gives the pin outs.

 

[dalebingham]

Thanks for the reply; Jeep service is checking, but haven't gotten back to me. I'll keep you posted.

 

[dalebingham]

My RV voltage at the hitch 7 pin connection is low and perhaps the issue. My Jeep works great behind several other vehicles, but not behind my RV. My RV will successfully connect to other toads and key lights but not my Jeep with it's Mopar toad harness. I'm thinking there may be a protective circuit in my Jeep that won't allow successful connection with low voltage. More next week after low voltage issue in the RV is resolved.

 

[Terminex]

just a thought, do you have a brake controller in the RV? I had the exact same issue you described when I forgot to unplug my brake controller in the RV. (I towed a trailer one week, and then the jeep the next week) The signals sent by the brake controller were messing things up.

 

[dalebingham]

Good thought, but no controller.

 

[dalebingham]

Looks like my old RV didn't have 12v power to the 7 pin connector, just 6 pins wired. Running 12v power to the correct pin on the RV fixed the issue. All lights on the Jeep are working when it's towed.

 

[georgewijatyk]

Definitely want to hear what “flashing” is being mentioned.

i have been flat towing mine behind my RV for a year with the mopar flat tow harness, and have never flashed anything.

only issue i encountered at the beginning was due to user error when i installed it.

i do not think the instructions are ver clear when you are connecting the wiring for the front bumper connector. I initially connected a couple wires wrong as it was not clear which end of the connector you are viewing when it gives the pin outs.

Hi Terminex, I am installing the wiring for the front bumper connector. I inserted the six wires into the connector exactly as pictured in the instructions on step 12 attached. However I believe that the diagram is facing the incorrect direction. I believe that the connector pins should be facing the reader, not the round insertion holes. Am I correct? Thanks!!!!

 

[JeepN3RD]

Looks like my old RV didn't have 12v power to the 7 pin connector, just 6 pins wired. Running 12v power to the correct pin on the RV fixed the issue. All lights on the Jeep are working when it's towed.

Ok I was JUST posting up about this exact same issue, I bet this is my problem too!!

 

[Terminex]

Hi Terminex, I am installing the wiring for the front bumper connector. I inserted the six wires into the connector exactly as pictured in the instructions on step 12 attached. However I believe that the diagram is facing the incorrect direction. I believe that the connector pins should be facing the reader, not the round insertion holes. Am I correct? Thanks!!!!

you are correct. that is the EXACT same thing I did when I first installed it. once I reversed them it was all good.

if they would simply label the picture to tell you that you were seeing the back of the connector, it would be all good.

 

[Down South]

If in doubt, use a multimeter to confirm correct pins to wire to.

 

[Kraxler]

I have the same problem. How did you get the connector open or how did you get the pins out? Thanks.

 

[cinap]

Lurking on this thread because I have this same harness and it doesn't seem to be working. The pins look fine on the connection, but can someone with a working setup please confirm how the wires should go into the fuse box (see step 60 in the screenshot). The ones that are labeled are correct, but none of the other 4 wires seem to be diagramed.

 

[Terminex]

Match the colors.

each fuse will connect a colored pair. And when i say color match, i mean the black wire gets match to the black and white stripe. Red matched to red and white stripe, etc…..

 

[cinap]

Match the colors.

each fuse will connect a colored pair. And when i say color match, i mean the black wire gets match to the black and white stripe. Red matched to red and white stripe, etc…..

Thanks, that's what I was assuming. It looks like the dealer installed it wrong because the colors do not match. I tried pulling them out to realign, but they are dug in like an Alabama tick. Anyone got a good method/tip for pulling these out without damaging them?

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