Are you using the D2D cable to connect the bypass and remote start together? You only need to connect bypass harness pins 2 (Green), 7 (Pink), 8 (Orange) to the car PATS harness pins 3 (Violet/gray), 4 (yellow/orange), 1 (Blue/brown) respectively.
I had to use a relay for the parking lights, the ford system draws more than 10 amps (potentially). I would like to hook up rear defrost and the heated seats, but couldn't narrow down which wires in the car were needed.
It took a few tries to program the bypass, and then my car wouldn't start either lol, sorry I don't recall what it was that I overlooked at the time. Just double check all your connections from the beginning and try again. Also, what does the diagnostic LED say? It flashes a code to help you narrow down failed starts.