7-Way Trailer Connector 12 Volt Circuit has Power All the Time

Updated 03/26/2015 | Published 03/25/2015

Question:

After disconnecting my travel trailer there is a 12v indicator light on my 7 pin electrical receiver plug that remains on and I am unaware if it suppose to. I do not want my vehicle battery to drain and any help or advice would help.

asked by: Justin

Helpful Expert Reply:

The 12 volt circuit on a 7-Way that was hardwired into a vehicle is going to have power all the time. Provided nothing is plugged into the 7-Way that draws power from the 12 volt circuit then it would not be a problem. The little LED light would take months to drain a vehicle battery if you were to let it sit all that time and never start the vehicle.

But there is a way that you can shut off power to the 12 volt circuit when the vehicle is off. You would need battery isolation solenoid # PK5231201.

The wire that goes from the positive battery terminal to the 12 volt circuit would instead go to the input side of the solenoid. Then you would attach a wire from the output side to the 7-Way. So basically it would install in line with the 12 volt circuit's wire.

On the front post you would run a wire from it to any circuit on the vehicle that only has power when the vehicle is on (like the radio for example). What the solenoid does is act like a gate. When the vehicle is on that front post is energized and the gate is open allowing power to go back to the 7-Way 12 volt circuit. When the vehicle is shut off the gate closes.

expert reply by: Michael H