Sponsored

Mopar Flat Tow Harness arrived

ForzaNature

Member
First Name
Jim
Joined
Jan 24, 2021
Threads
1
Messages
17
Reaction score
12
Location
Chicago, Il
Vehicle(s)
2019 Wrangler Sport JL
Bad wire on flat tow harness. After months of no problems, my left blinker stopped working when connected to the tow harness and RV. I've verified power from RV to my blue ox connector which is spliced into the original RV side of the tow harness. At the fuse connector junction box, I no longer have power on the red left blinker wire. Is there anyway to remove the wires from the jeep side connector piece or from the fuse junction box. I have no good way of testing the wire individually other than direct power on the connector pin does not show up on the fuse box side.
You might check the relay that switches between the jeep and the RV. I think they are located in the area of the taillights. Maybe swap the left and right relay??
Sponsored

 

2k6_tx_Dad

Active Member
First Name
Jeff
Joined
Aug 24, 2019
Threads
2
Messages
41
Reaction score
102
Location
Katy, TX
Vehicle(s)
20 JLR 6sp
Installed my Mopar flat tow harness this past weekend.
Read this thread twice before I started.
I pulled the entire front fender, not just the fender well.
I ran the wire through the interior from the right taillight.
No need to pull the steel bumper, once you pull the license plate mount, it's easy to plug the harness into the plate light and run the harness from left taillight to the right.

Jeep Wrangler JL Mopar Flat Tow Harness arrived 2021-10-03 09.01.01
 

roaniecowpony

Well-Known Member
Joined
Dec 4, 2018
Threads
144
Messages
7,238
Reaction score
9,284
Location
SoCal
Vehicle(s)
2018 JLUR, 14 GMC 1500 CC All TERRAIN
Occupation
Retired Engineer
Installed my Mopar flat tow harness this past weekend.
Read this thread twice before I started.
I pulled the entire front fender, not just the fender well.
I ran the wire through the interior from the right taillight.
No need to pull the steel bumper, once you pull the license plate mount, it's easy to plug the harness into the plate light and run the harness from left taillight to the right.

Jeep Wrangler JL Mopar Flat Tow Harness arrived 2021-10-03 09.01.01
Yeah, Mopar instructions about taking the liner out of the fender is rediculous. I've pulled that fender a few times as a single unit. Just keep some of those fender clips around. They do break occasionally when pulling the fender.
 

RonAZ

Well-Known Member
First Name
Ron
Joined
Mar 7, 2018
Threads
8
Messages
145
Reaction score
92
Location
Scottsdale, Arizona
Vehicle(s)
2018 JLUR
I installed Mopar harness in Oregon in my cousins shop. I tested with his pickup and his 10 year old motorhome electrical cable. Roadmaster I think. Everything worked. When I returned to Az I hooked 2018 JL up to my pickup for a test tow. I used a new Blue Ox cable. Jeep towed fine, but the lights were all screwed up. Test receptacle on pickup and it's good. Have the wiring pinouts changed over the years. Only thing different was the new Blue Ox cord.
 

JD Jeep

Member
Joined
May 16, 2021
Threads
1
Messages
16
Reaction score
7
Location
Texas
Vehicle(s)
2021 JL
For anyone interested, I documented my install of this harness. I ended up going through the interior for the install, which went smooth. Although getting through the wiring bundle in the firewall was pretty scary! We also ended up cutting off their proprietary connector and using our own to integrate better with our Invisibrake.


Thanks for producing this video!!! I found it very helpful given the IKEA-like instructions that came with the kit. I did notice that at 31:10 into the video you didn't lock the red clip in the tail light harness. I hope you went back later it locked it as you mentioned you weren't done yet.

For others planning to install using this method, here are some things I ran into that might help supplement this great video.

1.) I broke three of the fender clips removing the fender. If some of the clips survive but are still attached to the Jeep body, I think it's safer to take some needle-nose plyers (or fingers) and squeeze the backside of the connector before pulling them out to minimize damaging the locking mechanism.

2.) Spend some time researching how to insert/remove the pins in the proprietary connector on the front harness that connects to the umbilical cable. I never figured out a consistent way to insert/remove the pins, but managed to get lucky and completed it successfully after a while. If anyone knows how to do this, please let me know. I lost a ton of time dinking with this part!

3.) The wires going through the firewall on my 2021 Rubicon are wrapped together with harness tape so I'm guessing it's easier than having them loose like in the video, but still very difficult. It helped me to "carefully" cut two small holes in both sides of the firewall boot away from the wire bundle. Then I pushed my finger through the "interior side" hole in the boot and stopped once I could feel the "engine side hole". My wife then pushed a coat hanger wire in the hole on the "engine side" until it firmly touched my fingertip. she slowly pushed the wire into my fingertip while I guided it back through the interior side hole with my finger.

4.) The factory-installed tow package wire harness on my 2021 came wrapped with heat shield tape along the areas that are close to the muffler. My flat tow harness kit did not have this heat shield tape, but since you run it along the same path, I decided to purchase some and wrap the harness since the factory is now doing this on newer models. You might consider getting some before you start the install to save a mid-installation trip to the parts store.
 

Sponsored

roaniecowpony

Well-Known Member
Joined
Dec 4, 2018
Threads
144
Messages
7,238
Reaction score
9,284
Location
SoCal
Vehicle(s)
2018 JLUR, 14 GMC 1500 CC All TERRAIN
Occupation
Retired Engineer
...

3.) The wires going through the firewall on my 2021 Rubicon are wrapped together with harness tape so I'm guessing it's easier than having them loose like in the video, but still very difficult. It helped me to "carefully" cut two small holes in both sides of the firewall boot away from the wire bundle. Then I pushed my finger through the "interior side" hole in the boot and stopped once I could feel the "engine side hole". My wife then pushed a coat hanger wire in the hole on the "engine side" until it firmly touched my fingertip. she slowly pushed the wire into my fingertip while I guided it back through the interior side hole with my finger.

4.) The factory-installed tow package wire harness on my 2021 came wrapped with heat shield tape along the areas that are close to the muffler. My flat tow harness kit did not have this heat shield tape, but since you run it along the same path, I decided to purchase some and wrap the harness since the factory is now doing this on newer models. You might consider getting some before you start the install to save a mid-installation trip to the parts store.
On my large firewall grommet for the harness, I found there was an unused bump/nib intended for wire to feed thru. So, I ran it in that nib and it worked great. I had to puncture it with a coathanger and lube the harness to pull it thru.

Do you have a picture of that heat shield tape on the harness in the engine compartment?
 

JD Jeep

Member
Joined
May 16, 2021
Threads
1
Messages
16
Reaction score
7
Location
Texas
Vehicle(s)
2021 JL
On my large firewall grommet for the harness, I found there was an unused bump/nib intended for wire to feed thru. So, I ran it in that nib and it worked great. I had to puncture it with a coathanger and lube the harness to pull it thru.

Do you have a picture of that heat shield tape on the harness in the engine compartment?
Sorry for the slow reply. I didn't use any of the heat shield tape in the engine compartment since the existing harness I followed up from the firewall did have any on it. I only used it for the rear section that ties the taillights together that runs close to the muffler. Here's a picture for the rear section. I hope that helps if you haven't completed the install yet.

Jeep Wrangler JL Mopar Flat Tow Harness arrived IMG_5290
 

Jdw1

Member
First Name
Jeff
Joined
Mar 24, 2022
Threads
0
Messages
11
Reaction score
25
Location
Cannon Falls Mn
Vehicle(s)
19’ JLU Rubicon
Newby here, we just purchased a new to us 19 JL Rubi getting ready for retirement in a few years!

Very interesting thread! I ordered the mopar harness today from Milwaukee Mopar getting ready to tow the Jeep behind our motorhome!
 

RonLee

Member
First Name
Ron
Joined
Dec 31, 2018
Threads
2
Messages
15
Reaction score
22
Location
Polk City, FL
Vehicle(s)
2021 JLU Rubicon Ecodiesel, 2022 Gladiator
Occupation
Retired
So glad I went the CoolTech route :)
 

Eyeball

Well-Known Member
Joined
Dec 14, 2022
Threads
29
Messages
283
Reaction score
365
Location
California
Vehicle(s)
1997 TJ & 2023 JLUR
I just made an appointment for my dealer to do the same. 3 hours, $748.18 Total with harness. Sounds good to me.
I got a quote this afternoon from a dealer in SoCal for $700+ just for labor. Looks like I know I will be spending one of my Saturdays.

Edit: That was enough to tip things in favor of Cool Tech.
 
Last edited:

PapaRubi

New Member
First Name
Dave
Joined
Feb 26, 2024
Threads
0
Messages
1
Reaction score
0
Location
Olympia
Vehicle(s)
2019 Wrangler Unlimited Rubicon
Has anyone been able to get the white lock out of the plug on harness A?
I just had the same issue, doinking around with that connector for an hour, I finally figured out put a small screw driver in the large slot inside the connector and pry up, it will pop right back up. It does not come all the way out like the picture in the instructions. Also I did not have to remove all of the parts like the instructions show I was able to fish the cables along the paths with a snake. And was still able to secure the cable in many locations. Really expensive harness but it is a Mopar Part made for the JL.
Sponsored

 
 



Top