Flat Towing a 2010 Hummer H3 Behind Motorhome Battery Drain Issue Solution

Updated 06/21/2018 | Published 06/20/2018

Question:

I flat tow our 2010 Hummer H3 behind our 2015 JayCo Seneca. The H3 is wired with a TBC to, theoretically, keep the H3s battery charged. Im using an RVi Brake that is powered through the left 12v port on the dashboard the installer was specific about using the left 12v port, but didnt tell me why. Although theres power all the way from the Seneca through to the TBC at the H3s battery, after ~2 hours of driving, the H3s battery is dead which means the H3 needs to be jumped before I can detach because the transfer case is electronic!. Is there a fuses that I should be pulling on the H3 when flat towing so the battery doesnt drain? The key is in the ACC position and Ive made sure that ALL electronics lights, radio, etc... are off, to no avail.

asked by: Weylan B

Expert Reply:

If there is a fuse that should be pulled in your H3 when flat towing it will be mentioned in the owners manual under the section for flat towing procedures. I can't find anything that states that there is though. What we do offer that will help is a battery charge kit for vehicles that are being flat towed like the Roadmaster charge kit part # RM-156-25.

This will put a maintenance charge on the vehicle battery as you flat tow it to keep it topped off.

expert reply by: Jameson C