Re: [VAC] travel with propane on

["Dr. Gerald N. Johnson" <geraldj@xxxxxxxx>]

Trailer battery power is on a separate line from the brakes and running
lights. So running lights and brake lights can be working without
connecting the trailer battery charging line.

Unless the vehicle has a towing package with a relay to connect trailer
power only while the engine is running, connecting for trailer battery
charging requires a battery isolation module in the output line of the
alternator to allow charging of both batteries, but to prevent
discharging the starting battery with trailer lights. And to prevent
trying to start with the trailer battery because the wire won't survive
that.

Gerald J.