Dual battery switch/High voltage warning

[Surfingatmidnight]

This was my first summer with a '17 RZX that has dual batteries and the ProMariner battery system. Starting the year, I ran the boat with the switch on "combine batteries" without issue. Later in the year I found the manual states "the battery should only be on combine in case of an emergency." After a few days with the position on in On (not combined), I received a warning that the voltage on the crank was too high, and watching the voltage from the screen had it 18+ when any significant RPMs were hit. Switching to Combine immediately balanced the house/crank batteries to ~11/12v each.

What am I missing here? Should I be running the batteries in Combine, contrary to the manual and the switch or is there something wrong with the wiring? The boat is out for the winter but I am hoping to have this fixed before next season.

[bsreid]

If everything is working correctly the proper orientation is "on". My guess is you have a bad battery, if 11/12v is with the engine on that is very low, should be in 13s. Battery switches are also known to go bad. I would start by load-testing batteries and then check voltages with a volt meter at different locations to pinpoint an issue.

[chpthril]

"ON" is the correct switch position when the boat is in use.

My gut says the issue is with the Promariner ProCharge. If you can run the engine and have a $25 dollar volt/ohm meter from harbor freight, its easy to test.