You could cut off one connector of a PWM cable, but the best solution is to make your own. The best prices I've found are at
www.hansenhobbies.com and we've used them many times. Terminals and housings are
here. The economy wire
here is just fine, no reason to buy the deluxe wire. Unfortunately they only have 3-conductor wire, you can either peel off one of the conductors or just wire you got from somewhere else. Make sure you use wire that meets the size requirements of the manual (24 AWG for most uses). The crimping tools are
here, again, no reason to get the deluxe one, the economy one works great