I have a problem with my lights on my 16ft enclosed trailer. hey do not work when my truck is off. My friend has a chevy and the lights work fine when his truck is off. I was told by the trailer dealer that the fords are just this way. That the truck has to be in on position or running for the lights to work. Has anyone else had this issue or know the reason why. I have a tow package and an electric brake controller installed.

 

I have 16 foot car trailer and my lights work when the truck is off. You mean working if you would leave your lights on without the truck running???

 

The 12 volt aux hot is only hot when the key is in the on position. This will power the internal aux lights on some trailers. All of the other functions of the trailer lights will work same as the truck, key on ore off.

 

Indeed, the 12V switched power supply will not work with the key off. This is so that the truck's battery remains isolated from the trailer trying to drain it. To combat this, install an auxiliary battery on the trailer. $100 worth of parts and you'll be all set.

I would not want to have it set up like youre friend's Chevy... if that's actually the way his is wired, he's just asking for a dead battery in his truck from working in the trailer. I suspect he's got a battery on his though.

-Joe