I checked my wiring and it is the same...except for the kill switch of course. Only thing I can think is to take out the kill switch but I don't really have much hope it being the cause. But I have seen weirder stuff.
You are not getting power to your gauges and you are not getting beeps. Assuming those are operational;.... I would check power to each of those and see what you got. Form what I know the beeps tell you the MPEM has shook hands with the DESS key and all is good. Not sure you are getting that, which should lead to no start. Did see where you checked the DESS post and start button?
You verified all fuses are good to go? Did you say if this was a new to you ski or one you have had and just stopped working?