How to Wire 7-Way to Have 12V Trailer Power at All Times

Question:

The 40 amp fuse is good,and power to the fuse,what to check next,what makes it charge only when the truck is running

asked by: Joe B

Expert Reply:

Most vehicles equipped with a factory-installed 7-way will have the 12V trailer power circuit switched by the ignition key. Otherwise you could run the risk of the trailer draining the vehicle battery.

It is possible to wire a 7-way so that the 12V trailer auxiliary power circuit, usually carried on the pin at 1-o-clock (see photo please) remains active even when the truck is off. You would simply need to run a 10-gauge wire from the battery + terminal, through a 40-amp breaker like # PK54540, and on to the 7-way where it would need to attach to the appropriate pin.

expert reply by: Adam R