How Long is the Blue Ox Towed Vehicle Battery Charge Line Wiring Harness?

Updated 11/12/2025 | Published 11/11/2025

Question:

Is this charger also a diode, breaker, fuse. And what is length of wire to battery terminals and wire to 6 way plug?

asked by: Robert M

Expert Reply:

Hey Robert. The Blue Ox Towed Vehicle Battery Charge Line Wiring Harness item # BLU44ER is 25' long and uses 10 gauge wire. The PWM circuit uses diodes to protect it from voltage spikes. It requires 13.3v from your RV's 7-Way to charge a battery.

Are you having issues with your battery dying on your Jeep while being flat towed?

You can add this information and any other questions you have where it says Reply to Jerred H and I'll be happy to answer them.

expert reply by: Jerred H

Charge Line Wiring Harness
(click to enlarge)

Robert M.

11/12/2025

I am purchasing 2028 JL unlimited jeep toad that doesn't have charging line. My RV does have power for it. Wondering if this would be ok.

Jerred H.

11/12/2025

@RobertM Congrats on the new Jeep! The Blue Ox item # BLU44ER will work on your Wrangler. I recommend using the Roadmaster Battery Charge Line Kit for Towed Vehicles item # RM-156-25 instead. This will do the same job but has no circuitry that can be fried if you lose a ground or have an electrical issue. It includes a 15 amp circuit breaker that will automatically reset if there's an issue. Here are the parts you'll need to flat tow a 2018 Jeep Wrangler JL Unlimited: Tow Bar and Safety Chains - etrailer SD Non-Binding Tow Bar for Roadmaster Direct-Connect Base Plates item # e74ZR Base Plate Kit - Roadmaster Direct-Connect Base Plate Kit - Removable Arms item # RM-521453-5 - With Factory Steel or Plastic Bumper only. Wiring Harness - Roadmaster Diode 7-Wire to 6-Wire Flexo-Coil Wiring Kit item # RM-15267 Supplemental Braking System - Curt RVi Series Shadow 2 Flat Tow Brake System item # RVI94FR for a permanent install or the Curt RVi Series 4 Portable Flat Tow Brake System item # RVI44FR for a portable system.