[Mike Martus]

Before you throw the cable away and blame them take a look at the speed controller where they plug in. I was shown by the guys at Innovation FIRST that a small piece of flashing (thin plastic) is sometimes in the hole during the manufacture of the speed controller. Taking a thin sharp object you can remove this and the PWM wire will seat correctly.

We found this to be the case on many of the speed controllers.

This is a basic check we make on all controllers using a magnifying head gear to replace my old eyes.