How to Have an Always Active 12 Volt Circuit on 2021 Ford F-350

Question:

I am unable to get power to the trailer charge circuit using the 1st and 4th position within the female side of plug I tried the steps to answer to the same question for 2019 but to no avail. Using 12V tester there is power to the other blades within the plug but nothing to position 1 and 4 marked as - and + on the plug cover ed tow/haul drive mode, depressed brake pedal multiple times, checked and replaced fuse 26 as identified in owner manual as trailer tow battery charge had truck running, doors closed, i did not have trailer hooked up as Im trying to get 12V power to use for the power winch on my boat trailer.

asked by: Mike M

Expert Reply:

You do need to have the trailer hooked up in order to activate the 12 volt circuit on your 2021 Ford F-350. This is a pretty consistent pain point and the reasoning for this design choice is beyond me, but if you want you can have it always active by going a different route.

What you can do is run 10 gauge wire # 10-1-1 (sold by the foot), and connect it from the vehicle's positive battery post through circuit breaker # 9510.

expert reply by: Kyle S