I got a new trailer, light-weight. Same as mtpmike and others. For my '04 xA.

Hooking up the trailer "tail light" circuit, through a 3 wire to 2 wire "converter" (Tow Ready Taillight Converter 119130) drains the battery to near dead in about 5 minutes. But, there is no short in the trailer. I know this because I hooked up the same exact trailer circuit wires to a 12V powersupply & measured the current, and its fine at 3.6A. A short would be a lot more.

I am tapping into the wires that lead to the left tail light. Found the "tail light" circuit with simple multimeter.

If the additional 3.6A was exceeding the fuse rating of that circuit (10A I think) then the fuse would blow, but it wouldnt kill the battery so quick. I know others doing this have used these "unpowered" converters. But there are powered converters- direct + line to the battery. But still, that is to prevent blowing a fuse, not to prevent killing a battery.

A dead battery could be the culprit, but it shows 12.6V open circuit voltage, which acc. to the manual, is fully charged. I can run the 60W-head lights/radio for a long time, but hook up the trailer, and bam, radio dies, battery light comes on, battery gets killed right then. It seems like a short! but its not! The battery does seem to charge up real quick- so maybe its lost all charging depth, and nothing is wrong with trailer, I just dont get why headlights/radio are fine without trailer.

Anyone have any ideas?
-cil

 

It was a dead battery- having the lights on, trailer or regular, with engine off, killed it. Not sure why it was ever showing 12.6V- must have been "surface" charge. Overnight, read 5V. New battery, seems to work with trailer.