Using Battery Isolation Solenoid to Preventing Trailer Battery from Draining Vehicle Battery

Question:

I have a cargo trailer with a seven way trailer plug. I wish to add a battery to the trailer to run the interior lights of the trailer when the truck is not hooked up. I do not want my truck to drain the battery I put on the cargo trailer if I leave them hooked together. If I install a battery isolation solenoid, how would I wire this. What would I use as the ignition source? The Black wire 12 Volt I have coming from My truck seven way outlet Is a constant 12 V not an ignition.

asked by: Jay R

Expert Reply:

You'd want to install the battery isolation solenoid part # PK5231201 on the vehicle side of the wiring so that you'd have access to a keyed circuit to allow the 12 volts only to be active when key is on. To do this on the trailer side of the wiring would require you to be a bit more creative. You could use the running light circuit as the activation circuit so that only when the headlights or running lights are on the battery would charge.

expert reply by: Jameson C