Originally Posted by kayleigh0302
I'm aware the lights
should not be wired to the battery, the wiring harness on the trailer was recut and attached to harness. the battery wiring has not been touched. If I was able to afford to pay for someone to troubleshoot this that would of been my first choice.
Heck (or stonger) most of what I know about fixing stuff is because paying to have it done was not an option, or at least not a good option.
These things always boil down to a process of elimination and untangling, sort of like Christmas lights.
If battery loses charge while totally disconnected from trailer, it's battery, otherwise not battery. Battery could have a short inside that draws power down.
You mention that the trailer plug was re-done, possibly a cross over now exists between aux wire that would feed trailer 12 volt from tow vehicle to run lights or fridge
while driving, or wire to feed charge to battery from tow? Plug harness would be one place the wires for battery and tail lights
would all be in one place getting connected.
Your going to need a meter if you don't already have one, cheap one from big box store will work fine.
If battery is OK you need to check amp draw with the meter.
This has some info on settings for meter to test this.
How to Find a Parasitic Battery Drain: 9 steps - wikiHow
And video of someone doing it for a car.
Testing For Current Drain That Runs Down Car Battery - YouTube
Not too complex a process, just a PITA to work through the process.
I would test draw with tow/trailer plugged in and without. Just to eliminate/implicate plug wiring as a problem.
If you have a draw measured from battery with everything "off" it comes down to disconnecting things or removing fuses one at a time
until the draw stops, remove tail light bulb(s), 12 v interior light bulbs, fuse from water pump or entertainment devices, if you have an inverter that too.
If your already "know" about a tail light test draw using meter with that bulb in and then removed.
Once you know for sure what is drawing it's mostly just a matter of following those specific wires and finding the crossed connection.
I think Brian is concerned that there is a short which could heat up and cause a fire, could be, but the draw on battery would be pretty high when checked with meter if you have a wiring or full short in a device.
One thing that I don't always do but never regret doing is buying wire that color matches anything I re-wire. Makes life a lot easier if the brown wire at tail light is brown all the way to the trailer plug. If not for me, then someone else eventually.