Anyone know what these empty plugs are for?

[jmdesigns]

These are driver rear frame rail.

 

[texmudder]

If memory serves they are used for when you have the in bed 5th wheel plugs.

 

[Regular Cab Duallies]

These are driver rear frame rail.

Those are for the in bed trailer connectors (5th wheel/gooseneck) I think.

Plugs by rear bumper

Does anyone know what the 2 two prong plugs are for at the rear bumper? I see the fifth wheel plugs so I know it’s not them hoping it could be up fitter switch harness maybe but can’t find my power probe to check for power (in the middle of moving so everything is scattered) it doesn’t show in...

www.fordtremor.com

2015 F250 rear wiring harness connectors? - Ford Truck Enthusiasts Forums

1999 - 2016 Super Duty - 2015 F250 rear wiring harness connectors? - I'm trying to find out what the two connectors in the image are.. I've looked through the manual that I have and searched around on the web and find nothing. They're on a 2015 F250. upfitter switches were installed from the...

www.ford-trucks.com

Wiring harness on frame rear of truck ?

www.powerstroke.org