Float Mode and Tach Buzz

[Rob9550]

Took the boat out for the first time today and it was amazing! I was very impressed and got a few thumbs up from others on the lake.
I do have a few concerns, when in float mode both of the batteries stayed at 10v the entire day. When I picked up the boat yesterday the previous owner left the battery switches on. I had a small battery pack to jump them and both engines started with no issues. When I got home I put both batteries on a deep cycle marine charger all night and the charger stated they were both good. After a 20 min trip to the cove the Connext said that both here 10v. I was worried that I wasn't going to be able to start the boat but I had no issues. I also let the radio run for 2 hrs while swimming and didn't have any problems. Is the connext accurate with displayed voltage?
Also, I hear a buzzing sound coming from the port tach. Any idea what it is?
And lastly, when I first started the boat I had a check engine warning for both engines. Called the previous owner and they said to re-seat the clean out plugs. I did and it cleared the faults. Any ideas on this one too? I had an AR192 and I never had any warnings with the clean out plugs.

Thanks for the help.

 

[subysti]

unfortunately you will find that the connext system only displays the voltage of the house battery and not the starting battery. Its a known problem that I've discussed here many times and Yamaha doesnt care. Check your batteries directly with a volt meter and you will see your start battery is probably fine. The way the charging relay on these boats work is that it will recharge the start battery fully first and then charge the house battery. You will need to drive the boat around for a while until it charges the house battery. As you're driving the boat you will notice on the connext screen when this happens as it will jump to 13.6 or so volts. Also make sure the house battery is a deep cycle battery and not just a starting battery. My dealer just installed 2 starting batteries.