Pete is correct in that it would be best to contact Tekonsha for the latest information. The phone number is (800) 325-5860.
Chevrolet has had issues with trailer brake controller compatibility that make it almost impossible to know what to expect when you hook up your Prodigy. Some owners reported that the trailer brakes
didn’t work unless the head lights
were on and others said that the trailer brakes
would apply without pushing on the brakes
It looks like Chevrolet did away with a plug for the vehicle specific controller harness at the end of the 2004 model year
On newer models, look for 4 wires taped together in a bunch on the far left side under the dash. They should have white labels to indicate what each wire was for. The 12 volt wire was RED on 2004 Trailblazers but looked more like ORANGE on the 2005. Test this wire for 12 volts. Some owners have said that the wire was dead. It may be fused or running off of another circuit that is sometimes off. Check your owner’s manual fuse charts and install the correct fuse if necessary.
Wire Colors are as follows:
Vehicle **************** Brake Controller
ORANGE or RED --12 VOLT+ -------- BLACK
BLACK ----------- -GROUND ---------- WHITE
LT. BLUE ---- STOP LIGHT
SWITCH ---- RED
DRK. BLUE ------ TRAILER BRK. ------ BLUE