Flat towing issues with my 2021 Wrangler Sahara 4xe

[Mark H.]

Although we have towed our 2021 Wrangler Sahara 4xe from Florida to California, back to Arizona and then (closing out a round trip to Minnesota) without issue, we have experienced twice now, in the last 6 travel days, a dead engine battery which even if jumped, sets off a myriad of fault codes (92 the first go round). We have an Air Force One supplemental braking system which is supposed to trickle charge the engine battery (apparently to no avail). I am wondering if anyone else has experienced this and I must ask, according to the owners manual, for flat towing, after checking to ensure the transfer case is in Neutral by placing the transmission in first reverse, then drive, you are supposed to turn the engine off, but it goes into AUX, another push sets it back to RUN and a third push is requited to turn it OFF... is your foot supposed to be on the brake or not??

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[BigMaCro]

I don't have direct experience with this, but I reviewed the AFO braking system manual and the only electrical connections it has is to the towed battery for the breakaway system and the status light mounted on the rear view mirror. So it doesn't charge the battery, but will have negligible draw. Charging would come from a separate tow electrical harness for your indicator lights etc. What do you use for this?

 

[BigMaCro]

I've done more research (interested in doing this myself).

According to a thread at 4xe forums:
https://www.4xeforums.com/threads/h...e-behind-their-rv-and-has-some-data-on-it.192

the electric pump that boosts the brakes is active even with the Jeep off. So it will drain your battery. People are pulling fuse f34 which disables that while towing (also there's less assist so need to adjust your AFO pressure).

I do recommend charging the 12v battery from the coach, ideally with a dc to dc battery charger.

Also, after putting the transfer case in neutral, chifting transmission to drive and reverse, put it in park then you can turn off the ignition like normal. Take the fob with you outside of the Jeep.

 

[Mark H.]

BigMaCro, thanks so much for your input. My turn signal and brake lights are powered from the coach. I have noticed the review mirror mounted red lights do stay on at times even when stopped and disconnected. I will have to see why that is happening although I believe it is a symptom of something related to the brake assist cylinder attached to the brake pedal (?).

 

[JeepN3RD]

Yeah it is going to be related to the braking system I guess. I did not install brakes in my 4xe, flat towed 14+ hours one way with zero issues. For my brake and turn signals I run magnetic mount lights, via 4 pin plug) to back of the Wrangler. So basically my wrangler is doing nothing, not using any of the systems on the rig itself.

As for brakes, my 40' diesel pusher weighs 32k or so with fuel and "stuff" and has air brakes, etc. I literally cannot "feel" my Jeep behind me with braking or if I don't have it on there. It is not the most correct or legal answer but towed 10k miles or so without any issues, up/down Fancy Gap multiple times here at VA/NC border, up and down Blk Mtn in Asheville area.

Never made it out west so maybe those mountains would make me look for a solution. But I acknowledge you are doing it the right way, the legal way and overall a much better / more ethical human than myself as a non brake in toad dude.

Something you might consider is setting your brake system to the "lightest" possible setting so it is engaging less often? So you are using it, you are LEGAL, it has brakes and break away functions etc etc. but maybe if it does less stuff.. it would use less battery?

But your flat tow method, Tcase in neutral, R/Drive just to check, then PARK, then foot off brake I hit button until OFF and done. Lock my doors and walk away.

Also, I think I saw someone else mention same, all day towing / dead battery issue and they were starting their engine mid day (1 or 2 times) to let 4xe generator recharge the battery durign their trip.

Sam

 

[Mark H.]

Thanks so much Sam for your reply. Yes, I agree setting the system to the lightest possible settingight help and FYI, we have been to Fancy Gap, love it!

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