Here are the part numbers for the electrical connector for the heated grips. From member luckybum,
you can order connectors on line from www.mouser.com. You'll need the following:
(1) mouser p/n 571-2821051 connector body
(3) mouser p/n 571-2819342 single wire seal
(3) mouser p/n 571-2821091 wire connector
You'll only use 2 positions but it's best to seal the third position with an unused wire.
Added by sproggy:
For people in the UK/Europe the required parts can be obtained from Vehicle Wiring Products - http://www.vehicle-wiring-products.eu.
Search for 'Superseal Weatherproof Connectors'. You need the 3-way version which costs (May 2015) £3.93 + VAT. This is for a full plug/socket set although of course you need only half of the set.
One stop shopping in the USA: