Confused with a problem concerning trailer plug

[71ford100]

I am really really confused to what I have going on and looking for some help. On our '00 it has a trailer plug in the bed and also one by the bumper. For some strange reason I only have constant power to the plug in the bed. Everything else that is hooked up on the plug by the bumper works as well as the power. As for the one in the box nothing else has power to it. Both harnasses appear to go into one main harness so I'm not sure why one works but not the other.

I have checked fuses and everything appears ok (I did replace one still no difference in the bed). The in bed plug isn't corroded and I don't see any cracked wires.

Please help headed on a long trip tomorrow night with trailer in tow!

[SuperCrutyPS]

It may depend on how they connected the box plug. The one on the bumper is probably factory so that's why it works.

Did they tap the box wires into the bumper harness? Those connections may not be that good keeping the right voltages from getting to the pins.