When I wired this thing up a few years ago I didn't hook up the part of the wiring that gives a 12v feed to the trailer that charges the battery for the camp trailer. I need to do that now and I don't know where to tie into to get the 12v power that should only be on when the engine is running. I guess I could run a wire all the way back from the fuse box, but I was hoping I wouldn't have to do that.

Any help for me?

thanks

 

There is more than one type connector, but maybe this is the one you have...

 

hook the wire up to the battery direct with a 25 amp circuit breaker ,you want your 2 volt lead hot all the time so it will charge the break away battery when it is hooked up to the truck .

 

Also, on most of our rides, there is a place for a Relay, which holds your Trailer House Batteries out of the starting circuit, until you crank the engine. Then when the engine starts, it closes adding the Houses for charging. You may or may not have the Relay installed already ?

The reason for the Relay is...
The wire size which is satisfactory to charge the House Batteries, usually is not of sufficient size to deal with the current required to start. You should not hook the Houses up directly to your start circuit.

Old Dog is not wrong in wiring it like he said, but if you do, you'll need to remove that 25a Circuit Breaker, or, unplug your Trailer from your ride each time you start the engine. Then, reconnect it. Admittedly it's a little more trouble to set it up with the automatic relay connection, but it won't let you forget and burn up a wire.

If you don't want to seek out the OEM relay location (if you even have it) and use that, they make what is called a "Battery Isolator" Relay, which when installed properly, takes care of this for you by automatically disconnecting/separating the Auxiliary House Batteries from the Start Battery(s) while the engine is off, and when the engine is started, then brings them back inline for charging when the engine is started.

Additional Information:
Battery Isolators and Automatic Charging Relays - Blue Sea Systems
Example of Aftermarket Relays:
Battery-Related Products | Battery Isolators | Cole Hersee - Littelfuse