[VAC] Re: Why Car & Trailer Battery to Univolt?

["Harvey Barlow" <harveybarlow@xxxxxxxxxxxxx>]

Lan & Jim,

The isolator that Jim spoke of may already be provided by the factory.  I
think most of the later model tow vehicles, at least those with factory tow
packages, isolate the charge line when the ignition switch is turned off.
My faithful old '94 Ford only provides power to the trailer charge line when
the ignition switch is in the on position.  I've never looked for it but I
assume the ignition switch routes low amperage current to the relay which
actually controls charge line current.

Harvey