Darn it Mike beat me to it! Yes, it is the light for the compass at the helm. You can dim it as needed to maintain night vision. I know there will be a few issues with a boat that has as many systems as the Amel, but with the forum you should be able to find answers from people who have been there....and one or two that have literally written books on the Amel.
I might address your 12v main engine alternator issue. I have an older SM that was updated to the same engine I suspect you have, the Volvo TMD22. My 12v alternator sometimes does not want to wake up in the morning. What has resolved the issue was to rev the engine to about 2000rpm in neutral(go into engine room and locally activate the throttle linkage without putting transmission in gear) then quickly back to idle. Might take a try or two. It usually catches. Once woken up it is good for the day. Is your tachometer also showing no activity?
SV Annie SM37
cruising Pamlico Sound