Should 12V Pin On Vehicle Side Connector Have Constant Power

Question:

I have two trucks that both have 7 way trailer connectors. The 1:00 pin on one truck is hot all the time and the other one is hot only when the ignition switch is ON or in ACC. Which has the correct wiring?

asked by: Gary A

Expert Reply:

The 1:00 pin on your truck's trailer connector is designated for the 12V power circuit. It's very possible that the wiring on both of your trucks is actually correct. Some vehicles will have constant power while others will not, but neither situation necessarily indicates an issue.

If the 12 volt circuit is hot all the time on one of your trucks, even with the ignition off, this is normal and you do not need to worry about the battery draining. When this is the case, you essentially have a really long positive battery terminal that extends to the rear of the vehicle. If nothing is draining power from it or connected to it, it will not drain the battery.

For your other truck, as long as everything works as it should when connected to your trailer, the fact that it does not receive the same constant power at the 1:00 pin can also be normal.

expert reply by: Chris R