I read about this problem in the archives. So I have a car battery and relays in my mtcyl trailer...I was unable to find appropriate LED fixtures to replace all the lites so this was easier. Four brake lites in back. Battery lasts overnite when driving at nite...charges when I park. Lites take a lot of power, and the column switches aren't built for that. My tow dolly has only two 1157 bulbs so it doesn't seem to be an issue there.
2014 XLR 415AMP, 2011 F350 6.7 DRW, restored 82 Wing, 02 Shadow, 06 ST1300A, NRA Benefactors.