JLUR battery flatlining when flat towing

[mmayer813]

Nope... but I suppose that message would get annoying over time? Folk have asked us about forgetting to put the switch (in our solution) in the right position. If you were to jump in the Jeep after disconnecting and forgot to put the switch back to JEEP mode, you'll simply get this bulb-out message. The same thing would happen if someone were to inadvertently flip the switch while you were driving.

OK, so I retracted both sensor wires as shown on post 211, however, I do not get any error msg on my dash (21 Rubicon). Tail lights still function as normal. Any ideas? Maybe I need to pull those pins completely out of the socket?

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[RubiBlueJLU]

OK, so I retracted both sensor wires as shown on post 211, however, I do not get any error msg on my dash (21 Rubicon). Tail lights still function as normal. Any ideas? Maybe I need to pull those pins completely out of the socket?

If the sensor wires are completely disconnected, you should be good.
Be sure to do BOTH tail lights.
Tail lights will function as normal.
I only get a "tail/blinker" out message upon start up.

 

[mmayer813]

If the sensor wires are completely disconnected, you should be good.
Be sure to do BOTH tail lights.
Tail lights will function as normal.
I only get a "tail/blinker" out message upon start up.

Yep, both sides are messaged as put now, but everything is functional. Now, my charging circuit from the motorhome is not giving me any power!!! Never used that pin before, so I assume Thor missed something again! Ugggg...always something!

 

[RubiBlueJLU]

Yep, both sides are messaged as put now, but everything is functional. Now, my charging circuit from the motorhome is not giving me any power!!! Never used that pin before, so I assume Thor missed something again! Ugggg...always something!

With the wires unplugged, the jeep will not wake up as before. Solving the dead battery issue.
As a test, hook the jeep to the rv and plug everything in. Roll the drivers window down. Put the key somewhere away from the jeep.
Give it about 5 minutes. Go back and use a broom stick to press the brake pedal through the open window. The jeep should NOT wake up.
Then, go to the Rv. Turn the power on (start it if you want) and use the blinkers and brakes. When you go back to the jeep it should still be asleep.
You would only need a charge wire to the jeep if you are using a supplemental braking system that uses power from the jeep.

I have towed our Jeep (JLURD) over 2500 miles this way. Day, night, and rain. 2 days without disconnect. Never a dead battery.

 

[calixtoemilio]

This is an informative thread for many current and future Wrangler JL "toad" users. As many of you know, we make a custom toad wiring kit for the Wrangler JL so that the towing vehicle has the opportunity to control the Jeep's parking, turn, and brake lights. The alternative to our harness is a "universal" diode-based kit, but our kit; 1) has fewer connections; 2) all connections are made within the interior of the Jeep; 3) provides full 12v to the lights (whereas all diodes systems rob power); 4) our solution is 100% PHYSICALLY isolated from the Jeep electronics and computers so there is never a chance of back-feeding, etc.

But, let's discuss the battery "draw" problem from the original post. For the Jeep's lights - be it our system or a universal diode system, all of the power from the lights comes from the tow vehicle. As such, if you implement a system that just control's the Jeep's lights, then you will never have a problem with draining the Jeep's battery. However, many people elect to install an auxiliary brake controller inside the Jeep. These systems apply the Jeep's brake pedal when the tow vehicle brakes and the Jeep helps in applying stopping power. In nearly all cases, these aux braking devices utilize the Jeep's battery to function. As such, these kits when used over a period of a couple of hours or more, can deplete the Jeep's battery. So, if you plan to use an aux braking device, you should install a device that continuously charges the Jeep's battery as you tow. The aforementioned RVi Towed Battery device is an excellent product for this. For a clean install, owners should consider using a 6-pin umbilical cord and socket so the 4 light wires (left, right, parking, and ground) can also have a 12V charge wire within the same harness. In other words, only a single (6-wire) umbilical cord connection needs to be made. Note that we sell a "Deluxe" JL wiring kit that includes the RVi Towed Brake component, a 6-pin socket and a 6-wire coiled umbilical cord for this specific purpose.

https://www.cooltechllc.com/2018-je...harness-kit.html#/69-jl_tow_harness_kit-basic

Installation video cannot be seen because marked as “private”. How to watch it??? It helped a lot in my first jl.

 

[LukeDagny]

I've read all 20 pages, and think I understand the issue and solution. Multiple people stepped up and contributed. As a new JL owner, it made me happy that I joined this forum.

There are various ways to connect a JL as a toad, and I wanted to run my method by the collective.

My tow vehicle has both 4 pin and 7 pin sockets. I have a Blue Ox tow bar and brake unit. I don't want to go to the effort or expense to install a harness that controls the JL taillights.

My plan is to us magnetic brake/turn signals that are powered from my tow vehicles 4 pin socket. These lights will be placed on my metal bumper. Since the JL tail lights are not being used, my JL should stay in sleep mode.

To power my brake unit, I plan to run power from my tow vehicles 7 pin socket to a cigar socket that I will mount discreetly, under the dash of my JL. Since the power is coming from my tow vehicle, I won't need to worry about charging my JL's battery.

Did I cover all my bases?

 

[CoolTech]

Kudos to you for reading through 20 pages!!! Your magnetic tail light solution will avoid the waking up/battery drain problem! I would suggest that you consider a 6-pin socket on your Jeep. Run the Left Stop/Turn, Right Stop/Turn, Running Light and ground wires from this 6-pin socket to the rear of the Jeep and add a connector back there so you can easily connect the magnetic lights. With a remaining pin run a power wire up to the Jeep's battery... so that it is charging whenever you are connected. Now you can plug your brake device into the Jeep. You can plug it into the rear cigarette lighter adapter or you can install our PowerPort Kit so you can use the front cigarette lighter adapter.

 

[LukeDagny]

I would suggest that you consider a 6-pin socket on your Jeep. Run the Left Stop/Turn, Right Stop/Turn, Running Light and ground wires from this 6-pin socket to the rear of the Jeep and add a connector back there so you can easily connect the magnetic lights. With a remaining pin run a power wire up to the Jeep's battery... so that it is charging whenever you are connected. Now you can plug your brake device into the Jeep. You can plug it into the rear cigarette lighter adapter or you can install our PowerPort Kit so you can use the front cigarette lighter adapter.

I planned to install a 6 pin socket to get a power source, but my magnetic lights came with a 20' cord. I'll probably just plug that into my tow vehicles 4 pin socket, although, a single connection point, using only my 6 pin to 7 pin cable, would be easier.

I like your power port kit idea, but I usually have a GPS plugged into my front cigarette socket. I like that it powers off when I turn off the Jeep. I'll have to see if the brake unit's power cord can reach the rear outlet.

 

[CoolTech]

I'll have to see if the brake unit's power cord can reach the rear outlet.

If not, and assuming that's your preference, an extension is probably inexpensive via Amazon.

 

[TJDave]

I've read all 20 pages, and think I understand the issue and solution. Multiple people stepped up and contributed. As a new JL owner, it made me happy that I joined this forum.

There are various ways to connect a JL as a toad, and I wanted to run my method by the collective.

My tow vehicle has both 4 pin and 7 pin sockets. I have a Blue Ox tow bar and brake unit. I don't want to go to the effort or expense to install a harness that controls the JL taillights.

My plan is to us magnetic brake/turn signals that are powered from my tow vehicles 4 pin socket. These lights will be placed on my metal bumper. Since the JL tail lights are not being used, my JL should stay in sleep mode.

To power my brake unit, I plan to run power from my tow vehicles 7 pin socket to a cigar socket that I will mount discreetly, under the dash of my JL. Since the power is coming from my tow vehicle, I won't need to worry about charging my JL's battery.

Did I cover all my bases?

Wouldn't the Blue Ox brake wake the Jeep up when it presses on the brake pedal regardless if you are using magnetic lights? My Jeep brake lights activate when the pedal is pushed, even when off. I'm not sure, just asking.

 

[LukeDagny]

Wouldn't the Blue Ox brake wake the Jeep up when it presses on the brake pedal regardless if you are using magnetic lights? My Jeep brake lights activate when the pedal is pushed, even when off. I'm not sure, just asking.

I need to test my set up to confirm. It was somewhere in the 20 previous pages, but I thought the Jeep only came out of sleep mode when the Jeep's brake lights were activated/controlled by the tow vehicle through a harness.

The broomstick test with the window down should be the same as my Blue Ox brake box pushing on the brake pedal. My brake box communicates with the tow vehicle wirelessly via bluetooth. RF signals.

 

[CoolTech]

LukeDagney is correct. The Jeep will go into sleep mode a couple of minutes after it is turned off and the driver's door is closed. In sleep mode, the brake circuit lights are not energized and depressing the brake pedal will NOT cause the brake lights to activate. As such, this will not cause the Jeep to exit sleep mode.

 

[Alease]

So, I have a 2024 392 and contacted Kendall at CoolTech as I had the battery drain issues first time out. Below was his response. I believed his information and went with the switch instead of the battery charger option as I didn't want to be drawing down power from the battery.

The issue is that when *ANY* tow harness activates the rear lights, the Jeep will "wake up" and start drawing current. This happens because the rear light is on a circuit board and on that same circuit board is a "fault sense" wire that goes back up to the Body Control Module (BCM) and this causes the BCM to wake up the Jeep.
Quite simply, our fix kit (switch) "opens" this connection between the rear light and the BCM when you are towing. As such, the BCM never "sees" any voltage and therefore does not wake up the Jeep.

So, I paid for the switch, and I paid my mechanic $205 to professionally install it. Total cost was $252.95. and needless to say, it didn't work.
I contacted Kendall and he gave me every excuse in the book as to why his switch worked on my 2024 and then told me I should buy the RVI charger. I could have done that in the 1st place, and it would have been cheaper.

We went back and forth with multiple emails. Here are some of his comments.

Our switch DOES stop the battery drain. If you don’t want it, you can send it back and I’ll refund you fully - even though we don’t normally do that. But you need it. Without it, each time you use a turn signal, the Jeep will wake up.

Out Battery Drain Fix kit fixes the battery drain issue that is caused by the tow vehicle activating the rear lights. It fixes this on your 2024 as well. The reality is that in 2024 there is an add’l scenario that will wake up the Jeep which DOES NOT happen in 2018-2023 JL WRANGLERS. This is when the brake pedal Is moved by an aux braking system.

So, he finally agreed that his switch will not work on a 2024 and wants to put all of the blame on Jeep. Well Jeep didn't make his switch, nor did they sell me the switch and claimed it would work.
I do not normally bad mouth people, but Kendall will take no responsibility and still claims his switch works. I told him to send me the charger, the 6-pin plug and cord which I would have to swap out and we can call it even. He had no interest.
His final response below.

I hope you agree that it is Jeep that developed a product that flat out doesn't work as a tow vehicle. It was Jeep dealerships that kept replacing Jeep batteries most of the time under warranty but sometimes at the owners expense. Jeep couldn't figure out the problem.... but we did along with some help/testing of Jeep owners on the forum. As I have told you several times, the Jeep drains its batteries because it comes out of low-current sleep-state and wakes up. The trick is to find what is causing it to do that. The root of the problem on Jeep's side is that the NHTSA requires that Jeep notifies the driver if/when a light is not working. This is easy to do on a regular old-fashioned light bulb. When the filament breaks, there's no continuity. But on an LED, detecting a failure is much harder. So, on JL Wranglers, the LED light is on a circuit board. Each time there's 12v to the circuit board to turn the light on, a 12v signal is sent via a wire to the Body Control Module that confirms the light worked. Simple and effective. The issue is that when a tow harness like ours or any other tow harness activates a rear light (via the power coming from the tow vehicle), the circuit board feeds 12v to that wire back to the BCM... and THAT causes the Jeep to wake up and start consuming power. So. our switch simply "opens" the circuit between the light and the BCM while you are towing. This way, a 12v signal can't get to the BCM and the Jeep doesn't wake up. So, despite your claim, "this fucking switch" DOES work and is used by MANY owners who finally have a solutuion to their battery drain issue. So, it works perfectly for 2018, 2019, 2020, 2921, 2022, 2023 Wranglers. But then along comes 2024 and a customer comes back to us and says he still has the battery drain issue. Together, we determined that the switch IS WORKING. The tow vehicle brake lights or turn signals do not wake the Jeep up when the switch is in the TOW position. SO what is going on?? As it turns out, Jeep revised the whole braking circuit. Like you, I assume there was a good reason they went to a potentiometer (so they can tell how far the brake pedal is being pressed).... but what the Jeep engineers didn't think of is the people who use the Jeep as a TOAD. Namely, only on 2024's.... whenever the brake pedal is moved, that action causes the Jeep to wake-up. As far as I know there is NO known fix for this. This is why I said a temporary resolution is to disconnect the connector. Yeah, it's an ugly solution but it that or live with the dead batteries.

I don't think anyone on this board should buy anything from him. He won't stand behind what he sells. He finally updated his website saying his switch will not work on 2024's.

Steve

 

[roaniecowpony]

So, I have a 2024 392 and contacted Kendall at CoolTech as I had the battery drain issues first time out. Below was his response. I believed his information and went with the switch instead of the battery charger option as I didn't want to be drawing down power from the battery.

The issue is that when *ANY* tow harness activates the rear lights, the Jeep will "wake up" and start drawing current. This happens because the rear light is on a circuit board and on that same circuit board is a "fault sense" wire that goes back up to the Body Control Module (BCM) and this causes the BCM to wake up the Jeep.
Quite simply, our fix kit (switch) "opens" this connection between the rear light and the BCM when you are towing. As such, the BCM never "sees" any voltage and therefore does not wake up the Jeep.

So, I paid for the switch, and I paid my mechanic $205 to professionally install it. Total cost was $252.95. and needless to say, it didn't work.
I contacted Kendall and he gave me every excuse in the book as to why his switch worked on my 2024 and then told me I should buy the RVI charger. I could have done that in the 1st place, and it would have been cheaper.

We went back and forth with multiple emails. Here are some of his comments.

Our switch DOES stop the battery drain. If you don’t want it, you can send it back and I’ll refund you fully - even though we don’t normally do that. But you need it. Without it, each time you use a turn signal, the Jeep will wake up.

Out Battery Drain Fix kit fixes the battery drain issue that is caused by the tow vehicle activating the rear lights. It fixes this on your 2024 as well. The reality is that in 2024 there is an add’l scenario that will wake up the Jeep which DOES NOT happen in 2018-2023 JL WRANGLERS. This is when the brake pedal Is moved by an aux braking system.

So, he finally agreed that his switch will not work on a 2024 and wants to put all of the blame on Jeep. Well Jeep didn't make his switch, nor did they sell me the switch and claimed it would work.
I do not normally bad mouth people, but Kendall will take no responsibility and still claims his switch works. I told him to send me the charger, the 6-pin plug and cord which I would have to swap out and we can call it even. He had no interest.
His final response below.

I hope you agree that it is Jeep that developed a product that flat out doesn't work as a tow vehicle. It was Jeep dealerships that kept replacing Jeep batteries most of the time under warranty but sometimes at the owners expense. Jeep couldn't figure out the problem.... but we did along with some help/testing of Jeep owners on the forum. As I have told you several times, the Jeep drains its batteries because it comes out of low-current sleep-state and wakes up. The trick is to find what is causing it to do that. The root of the problem on Jeep's side is that the NHTSA requires that Jeep notifies the driver if/when a light is not working. This is easy to do on a regular old-fashioned light bulb. When the filament breaks, there's no continuity. But on an LED, detecting a failure is much harder. So, on JL Wranglers, the LED light is on a circuit board. Each time there's 12v to the circuit board to turn the light on, a 12v signal is sent via a wire to the Body Control Module that confirms the light worked. Simple and effective. The issue is that when a tow harness like ours or any other tow harness activates a rear light (via the power coming from the tow vehicle), the circuit board feeds 12v to that wire back to the BCM... and THAT causes the Jeep to wake up and start consuming power. So. our switch simply "opens" the circuit between the light and the BCM while you are towing. This way, a 12v signal can't get to the BCM and the Jeep doesn't wake up. So, despite your claim, "this fucking switch" DOES work and is used by MANY owners who finally have a solutuion to their battery drain issue. So, it works perfectly for 2018, 2019, 2020, 2921, 2022, 2023 Wranglers. But then along comes 2024 and a customer comes back to us and says he still has the battery drain issue. Together, we determined that the switch IS WORKING. The tow vehicle brake lights or turn signals do not wake the Jeep up when the switch is in the TOW position. SO what is going on?? As it turns out, Jeep revised the whole braking circuit. Like you, I assume there was a good reason they went to a potentiometer (so they can tell how far the brake pedal is being pressed).... but what the Jeep engineers didn't think of is the people who use the Jeep as a TOAD. Namely, only on 2024's.... whenever the brake pedal is moved, that action causes the Jeep to wake-up. As far as I know there is NO known fix for this. This is why I said a temporary resolution is to disconnect the connector. Yeah, it's an ugly solution but it that or live with the dead batteries.

I don't think anyone on this board should buy anything from him. He won't stand behind what he sells. He finally updated his website saying his switch will not work on 2024's.

Steve

Steve, I installed the Mopar tow harness in my 2018 JLUR. When I would tow it for one day, the batteries would be drained. Last trip, I simply disconnected the batteries, checked and it still had tail lights/brake lights, and turn lights. Got to my destination and all was well. I towed without my RVi brake. But, I'm going to wire a socket for it directly to the hot lead on the plug on my bumper. My patience with all the "high tech" solutions has worn out.

 

[LukeDagny]

I don't think anyone on this board should buy anything from him. He won't stand behind what he sells. He finally updated his website saying his switch will not work on 2024's.

I know it's frustrating when you find a flaw in somebody's product. His statement;

I hope you agree that it is Jeep that developed a product that flat out doesn't work as a tow vehicle.

Is BS. I've set up two Jeeps for flat towing. My first was a 2005 LJ, and the second is my 2021 JLUR.

I was a little disappointed that the tow bar for my 2005 did not work for my 2021, but the brake system and wiring was not a big deal.

Since I have the OEM metal bumpers, a $35 pair of LED brake/turn signals from Harbor Freight do the job. I did not have to tie into the JL's wiring harness. The 7 pin to 6 pin cable from my tow vehicle feeds the LED turn/brake lights.

CoolTech was helpful with my questions when I was figuring out how to set up my JL.

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