I hooked up a new trailer brake actuator that required tapping into the
cold side of the brake light wiring at the brake pedal switch. It also
required a good ground, which I didn't have the first time I tested the
actuator. The ground I chose was at the dash, and was not sufficient.
The actuator buzzed loudly when the slider was moved and after a couple
of other wiring checks I relocated the ground wire to a solid chassis
point. The actuator stopped its buzzing, and works properly.
Immediately thereafter I noticed my cruise control wouldn't come on.
Fuse at the fuse block is fine.

I realize that the poor ground probably resulted in 12 volts possibly
being looped into the cold side of the switch, but that shouldn't have
been a problem since that is what happens when you step on the brakes
(to turn on the brake lights and/or turn off the cruise control).

Anyone analyze this differently, or have any idea of what damage might
have been done if any - and where to look first?  Thanks