jaywoodz
Member
- Nov 12, 2012
- 522
- Boat Info
- 1999 Sea Ray 310 Sundancer
- Engines
- Twin 350 MAG MPI Horizon w/V-Drives
You can set up a voltmeter on the terminals and get a reading. Then, holding the voltmeter in place, have someone crank the engine and compare to the "unloaded" reading. You should have a voltmeter on your breaker panel too. You can look at that when they're cranking. Do you know how old the batts are? They might still have the month/year stickers in place. ie: E8 would mean May of 2008 (5th month of 2008).
This was the panel on my previous boat. The two lowest meters are DC VOLTS (to the left) and DC AMPS (to the right). The switch just to the left of the VOLT meter lets you select port or starboard. Yours probably looks different (this boat was a 1989) but pretty much all SRs have this setup in the panel.
I only had 3 on my 340DB. If you do find the stbd bank to be week, replace both (they are likely connected in parallel) at the same time, even if one is ok and the other is bad. Sounds like your batts are in a difficult place to access. Typical of boats!
Yes, I have a meter for both AC and DC. Unfortunately, I can't switch between port and starboard like you could. I'll check all the info you posted and get back to you. Even if I switch the batteries, and it doesn't spike and the MFD stays on during crank, I may still have my issue. I did do an emergency start, and the MFD didn't cut off.. it dimmed though. I'm guessing that the DSM300 may be giving me problems.