[Dangerous Doug]

I would take a good, long look at the wiring schematic, and then check the inputs/outputs for shorts before I put another $900 box in it. tnlprt up above had a grand idea to send the box back to MSD for analysis. It's long past the warranty, but at least they can narrow down the root cause to something internal to the box or externa---meaning your wiring harness.

Good luck,
DD