15’ RZ2 only cranks and starts in combine mode?

[patryk]

I just got my boat back and it only cranks over and starts when the switch is in combine mode. It won’t start at all when it’s in the on position. Batteries are brand new, and checked all the connections and wiring, and it’s correct. Any suggestions?

[JohnnieMo]

Batteries may be new but are they fully charged? It only makes sense that the cranking battery is either dead or not connected properly.

[patryk]

They are fully charged. I read something once like the ACR or Isolator could be the problem, but can’t find anything about it when looking now.

[chpthril]

When diagnosing an electrical issue, the best way to determine a battery's state of charge, is to measure it with a handheld digital volt meter. We dont want to trust the helm gauge or a charger.

The ACR only effects charging distribution from the alternator, when the engine is running, and bank isolation when engine off. No starting current passes through the ACR/isolator.

[scoot18]

Batteries are brand new, and checked all the connections and wiring, and it’s correct. Any suggestions?

Can we ask what was the reason for replacing the batteries? Did you have this same scenario prior to replacing the batteries?

[patryk]

I did have same situation before changing batteries. Apparently the isolator is bad. Thanks for the help!

[chpthril]

The switch may have suffered a mechanical failure and the cranking bank input is not making connection with cranking bank output, but in the combine position, house bank is connected to cranking bank output.

A basic volt meter will end any speculation and guessing.