[Alan Anderson]

Do any of your other actuators (motors, relays, servos) work?

What pins on the Digital Sidecar are the control ("PWM") cable from the Spike connected to?

Are all three of the power LEDs lit on the Digital Sidecar?

Does the Driver Station display the word "Enabled" or the word "Disabled"?

What does the Driver Station show as the battery status?

What is the Robot Signal Light doing -- is it flashing, or is it on steady?

It's a lot of questions, but they'll help pin down where the problem might be.