1994 Hatteras. 12v92’s. The station screen (active,troll,low idle) sometimes responds to active then kicks back out) at one point boat went active and in gear by itself even though throttles are in neutral. First thought it was voltage. Had 3 out of 4 batteries bad and constavolt was bad. Replaced all but still not working. Any suggestions? Florida Detroit coming out today but said they had never seen this before.