GMC Repair: MBEC/Power Seats, amp fuse, electrical center

Question
I was having my car detailed yesterday and the workers had the seats powered all the way forward.  They did something that has blown the MBEC (50 amp) fuse in the underhood electrical center.  Any idea what?  The seats won't move and the windows don't work on the right side.  I bought a new fuse and popped it in and it blew right away.  I've tried to inspect the connectors and they seem good.

Answer
Ken

Check the underseat wiring harness,make sure its not rubbing against the seat adjuster and rails,ive seen the harness rubbed through at the rear corner of the seat track were the harness goes up and into the seat,check both front seats,also attempt to move/minipulate the harness and replace the fuse.

ED