If you put the connectors on the DRIVER end, they don't have to be sealed. Try these:

You can use THIS wire for motor cables and home/limit switches. Ground the drain wire ONLY at the driver end.

http://cgi.ebay.com/Servo-Motor-Wire...3286.m20.l1116

These gold-pin connectors are good and fairly cheap:

http://cgi.ebay.com/ws/eBayISAPI.dll...%3D4%26ps%3D42

CR.