Hello.I have 2 water pumps that run off acc switch to their own switch.They were working last year.They won't turn on unless i combine the dual batteries.But everything else like bilge pump,blower,radio etc... work without combining batteries.I have the second batt for stereo and amps.The main batt is a sea volt amg 3yrs old,that gets stored 9 months a year.I charge it about once a week but sometimes forget a week.But all the other accecories work off it.Also i drained it completely once last year at start up.Confused as to why everything else works without combining batteries except pumps.Any suggestions are apreciated.
