The accessory connector located just in front of the battery on most models has 4 wires in it. Different circuits are available in this socket and the mating plug is available from the dealer to use this as power source for different things as seen in the lower pics on this page.
This is the plug that is switched power from the accessory switch on touring models.
I believe these are the dealer numbers for that part.
72114-94BK - sealed socket housing
72154-94 - secondary lock, 4 socket
72191-94 - stamped and formed socket (pins)
These are the designations for the wires in that plug in earlier models as shown in the pic below.
In later models they are located under the seat in a black or dark gray connector as shown in the second pic.
pin 1 - O/R
pin 2 - R/Y
pin 3 - O
pin 4 - BK
NOT to be confused with the Data Link Connector (#91) shown in this picture.
These are the different configurations for connecting accessories to the accessory plug under the seat.
How to disassemble the plug
This is one of the types of accessory adapters that can be used in this plug.
Linear Mode
