Hey all I've tried searching but can't seem to find my answer .
on my 06 3500 I have no 12 volt power to my trailer plug on the back of the truck. I thought there was a fuse but can't seem to find one , all the other lights work fine ?? No power with or without truck running

 

You're going to need a probe tool to isolate the problem. A tool that connects to the positive and negative terminals of the truck battery.
Check for 12v positive at the plug. Be sure that you have truck lights on, or blinker, and are checking the correct pin.
If you are getting 12V then it's probably a problem with the ground. If no 12V then back probe the plug to ensure the plug is not faulty.
Use the probe to check for ground also.

 

I found the problem the trailer tow fuse was blown for some reason I thought that was for the tow/haul so didn't Check it carefully. Thanks for the input tho