[EricH]

Before you continue, could you answer a couple of questions?

1) What is the RSL light on the Sidecar doing?
2) What are the Jaguar lights doing? (translation: are they even getting a signal?)

That could have a large impact on what the problem is. At this point, it could be the DB37 cable, the Sidecar itself, the Jaguars, the PWMs, or something in the code. Those lights will limit the number of places that need checking.