[Jon Stratis]

In the interest of helping teams develop proper troubleshooting techniques, this is what i would do:

1. Power on the robot. Look at the Spike. Is the LED on (It should be Orange)? If not, check the power going into the spike (ensure the breaker is in place, and you read 12V between the inputs on the spikes, lined up with the markings on the spike (+12V and GND). Check the fuse on the spike itself, make sure it's working. If needed for testing purposes, this can be replaced with one of the 20A snap action breakers used for the PDB.

2. Look at the digital sidecar. As you indicated, the LED next to the relay output lights up. Use a multimeter to verify the appropriate relay pins are powered. Take special note of the orientation of the PWM cable when plugging it into the sidecar. The black wire should be on the outermost pin, and the white nearest the center of the sidecar.

3. Look at your PWM cable. Ensure all 3 wires are continuous (ie nothing got cut accidentally or pinched under a screw by the mechanical team). Check the output pins on the PWM cable to verify the proper pins are being powered when the relay is "turned on" from the sidecar.

4. Plug in the PWM to the spike. Ensure when you do that you plug it in in the correct orientation - the black wire should be closest to the fuse, with the white wire closest to the power input terminals. Seating it can require a little wiggling - it can look like it's in without actually being seated inside the receptacles. If in doubt, take the cover off one and plug it in without the cover - you'll see how it's supposed to sit in.

I would say your problem is most likely one of two items: Either the PWM cable is not fully seated in the spike, or it's not plugged in in the correct orientation in either the spike or the sidecar.