I own a 1989 Carver 38 w/454 Mercruisers. I noticed both voltmeters indicating 13.5v when the port engine running (normal). When starboard engine running only 12.0v on both meters indicating no charging from starb side. I am thinking my starboard alternator isn't charging. Where do I start looking or what all to suspect? I don't believe this is normal. Thanks!
:welcome: to iboats
Your alternators nor batteries should be connected to both batteries. Each alternator should recharge one bank only, and one side should also charge the house batteries, maybe a generator battery. You should have battery switches and they should be on/off type, or bank 1/ bank 2 / both.
Do the meters your discussing show the voltage reading all the time or just when the key is turned on?
What type of switches do you have?
Can you take some pics of your setup?