How to Wire 7-Way To Get 12V Power Even with Vehicle Ignition Turned Off

Question:

My 2017 ford 2507 prong plug in the rear of the truck has no power at the 12 V plug to run my trailer lights inside the trailer the courtesy lights inside when the truck is not running I’m looking for how to power the plug at the 12 all prong so my truck is off I will have powers inside my trailer it works with my buddies GMCGMC but doesn’t seem to work with my Ford

asked by: Giovanni

Expert Reply:

It sounds like you are wanting to have 12V power at the 7-Way connector on your Ford truck even when the truck's ignition is off.

With factory/OEM wiring, the availability of 12V power with the ignition off will actually vary between truck manufacturers. Generally speaking, GMC trucks tend to always have an active/hot 12V pin at the connector even when the truck is off. The 12V circuit on Ford trucks on the other hand usually require the ignition to be on for the wire to have power. This is likely why this application worked perfectly on your buddy's truck but not on yours.

To wire the 12V pin so that it has power at all times, you simply need to run 10 gauge wire like # 10-1-1 (sold by the foot) from the truck battery's positive terminal through a 40 amp breaker # PK54540 and then to the 7-Way 12V pin (typically 1 o'clock position).

expert reply by: Chris R