I know mine is there, but I can't find it. When I got the bike, I did not have to switch on the accessory switch for the seat to work. Then the seat stopped working. I took it to the dealer and it came back working. Then I noticed that I had to switch on the accessory switch to make it work now. I can't find the original plug now. I took it back to the dealer and they told me that there wasn't another one. I am assuming there was a problem with the plug, so they either hid it or cut it off altogether. If anyone finds the time to take a photo under their seat showing both plugs, I sure would appreciate it. I'll send it over to my dealer and let them know that it's time to fix my bike the right way.
I hope this helps. There are two female connectors under the seat of my '09 SEUC:
Heated Seat (factory label) 4 pin connector with only two wires;
Orange w/Red stripe - from P&A (power & accessories) 15 amp fuse
Black - Ground
ACC (w/rubber plug and my label) 4 pin connector with 4 wires
Orange w/Red stripe - from P&A 15 amp fuse
Red w/Yellow stripe - from Brake Light circuit
Orange - from fairing ACC switch
Black - Ground
ACC connector is fed from harness under fuel tank.
Heated Seat is fed from harness behind fuse block on left side of bike, adjacent to battery.
Now go get 'em!! Good Luck
Tom P.