There is no real good reason changing out the trailer safety lights if you are trying to save DC Power on your trailer batteries. The Trailer safety lights run off of the truck start battery system not the trailer batteries...
These safety lights are DOT approved when the trailer folks built the trailer. The LED replacement bulbs/boards for the 1157 automotive bulbs may not be DOT approved to use for the trailer tail light assemblies. Using replacement LED lights for trailer safety lights may have to use a complete DOT LED Lamp assembly...
Since these lights are powered by the 12VDC truck start battery system you will not gain any useful trailer installed battery DC Power savings wise.
Something to check with DOT/DMV about at any rate...
Just my thoughts here...
Roy Ken
My Posts are IMHO based on my experiences - Words in CAPS does not mean I am shouting
Roy - Carolyn
RETIRED DOAF/DON/DOD/CONTR RADIO TECH (42yrs)
K9PHT (Since 1957) 146.52M
2010 F150, 5.4,3:73 Gears,SCab
2008 Starcraft 14RT EU2000i GEN
2005 Flagstaff 8528RESS