Problem with Prodigy on '08 Treg

[Lemontree]

I thought I had it made when I found the four prong connector wrapped in foam under the dash. I located the 12v (red/yellow), ground (brown), blue to blue, and black/red...supposedly the brake switch. I have read on this site to tap directly into the brake switch wire, but there doesn't seem to be one close by. I cut the plug and wired the Prodigy to the corresponding wires (including the black/red brake switch) and I get a n. c. on the readout when hooked to the Airstream. My Chevy 2500HD works perfectly with the same model Prodigy. I'm running out of ideas. Has anyone had success hooking up a Prodigy on an '08?

[ericwarren]

finally got my envoy to work...turned out it was a bad controller!
the issue may be the voltage. When the brake is not pressed, there is 3-4 volts flowing. In some controllers this may be enough to mess them up. The envoy takes 10 volts to activate.