Where is electric brake controller plug?

[jspringator]

My new Prodigy came with a plug and play installation cable that supposedly plugs in my Suburban (it has the tow package). Where do I plug it in?

[HowieE]

Not sure GM was up to plug and play in 99. GM's idea of a towing package is to provide the alternator and brake feed wires through the driver's side frame rail with the owner finishing the job. My 97 I had to wire the controller in and wire the plug at the rear.
If this is the case in 99 you should find the free ends of a heavy blue wire and heavy orange wire coming up on the fire wall just around or above the steering colume. The heaver wire is intended as the battery feed to the trailer and the smaller wire is intended for the brake feed to the trailer. I use the heaver wire for the brakes to reduce voltage drop in the brake circuit. You can pick up a voltage source for the controller on the post at the rear of the underhood fuse block. Coming off the post to a 30 amp circuit braker, that you install, and then to the controller.
You should find the 2 wires I mentioned above at the rear end of the drivers side frame rail. some years they are tucked inside the frame and you have to fish for them and latter years they are attached to the harness after it comes out of the frame and are visible.

[jspringator]

You are right; the 99 Suburban did not have the plug, although I understand the 99 truck may have if it has the newer design.