House and crank battery readings

[Germaine Marine]

Just went out to my boat to verify. Key on engine off does display house and crank voltage with battery selector at position 1.

If you have a (1) then it sounds like we are talking different switches. If my mind serves me right the factory dual circuit switch reads... On/Off/Combine

Dont know if we are talking different things or if you have a different switch and different isolator...

[JCP]

Actually not sure what mine says, but first position from off (not combine)

[chpthril]

Tige boats come with the OFF/ON/COMBINE dual circuit plus switch, since about 2012. The difference is, the isolator combiner they have uses over this period. Even though it has changes, the basic operation and schematic has not changed much.

[Jetjock15]

Yes I have the switch but regardless of if it's in combined or not the screen should read crank and house volts. Mine shows crank zero until engine is running then reads, I assume from the charging circuit.

[Germaine Marine]

My boat was the same way..... It is how the software was written within the smart isolator is my guess.

[Germaine Marine]

I changed the isolator from the proloso charge to a blue ACR. I now have readings for both when not running which is why I think it is isolator....

[Jetjock15]

Oh that's very interesting. Can you tell me why you changed the isolator? To the blue ACR? Is th isolator the little box the hot lines run into out of battery? Had the clear cover and some lights

[chpthril]

Unless some nerd has designed a FUBAR'd circuit that only has voltage on it when the engine is generating RPM, then what source the Murphy uses to show alternator voltage, should static battery when engine is off. Changing from distribute on demand device to an auto combining relay changes nothing, regarding what circuits get voltage.

Their differences are small. The DOD send alternator output to which ever battery bank needs it, however, the helm and engine are already supplied by a battery. therefore, alt charge or no alt charger, their will at least be static battery voltage present. The ACR has alt charge going to main cranking bank first, then through the relay to the house. However, it never stops supplying the main cranking.

At the end of the day, both setups do a very similar job, just a little different.

Would love to see a Murphy schematic on where that voltage display that reads zero when engine off, gets its voltage input from. I cant come up with one reason for this to be an intentional design.

[JCP]

If you have a (1) then it sounds like we are talking different switches. If my mind serves me right the factory dual circuit switch reads... On/Off/Combine

Dont know if we are talking different things or if you have a different switch and different isolator...

Just verified. Battery switch labeled off/on/combine. Isolator is a Proloso.

[JCP]

Oh that's very interesting. Can you tell me why you changed the isolator? To the blue ACR? Is th isolator the little box the hot lines run into out of battery? Had the clear cover and some lights

That is the isolator. Notice that the isolator leads connect to each battery positive terminal through a unique terminal fuse. Verify that you have 12 volts at the battery post and at the terminal heading to the isolator with engine off. If the isolator lead has 0-3 volts, you have a blown terminal fuse.
This is what my terminal and fuses look like. (we have the same boat). http://www.ebay.com/itm/Blue-Sea-Mar...ZY45sQ&vxp=mtr

[Jetjock15]

Great point. I'll check those fuses tomorrow.

[Rustydoc]

Hey guys. Found this post which similar issues to my 2015 z3

House 12.
crank 0 with engine off and 12. when on position with engine off.

have promarine charger
promarine isolater but it is even harder to see than the batteries

Problem Is — boat started when in water on trailer but soon as I shut it off 5min later (in middle off lake) would’nt start. When I saw the crank battery at zero I thought I’d ran the crank battery down.

wouldnt boost on crank battery. So I tried boosting from house battery and it started and ran great till turned off.

changed the crank battery.
Again start it up first time and then wouldn’t restart once it was turned off. Seems to start about one and every 10 tries. Had the battery charger on all last night

Seems to start about one and every 10 tries. Had the battery charger on all last night.

when it doesn’t start the gauges all flicker but don’t go to their proper spot when the engine key is turned on when you go to crank it.

it makes a single click and sometimes 2 click sounds that seem to be coming from the starter relay on the top of the engine block but it doesn’t turn over.

I am wondering whether I fried the pro mariner ACR by plugging in the charger when it was in the on or combined position? It seems to have power but not getting to the starter?

I also noticed a bit of water in the buttery tray. Found a leaky bag and fixed it but maybe something got wet a week ago.

seems like starter stuck or fried unless I fried the acr if that is possible


any ideas?

[chpthril]

I am wondering whether I fried the pro mariner ACR by plugging in the charger

A properly functioning charger would not damage the ACR or anything else.

Seems to start about one and every 10 tries.

This points to something other then a charging problem. A battery thats dead on try #1 will still be dead on try #100. But a bad connection or issue within the cranking circuit, can change from one start attempt to another.

Going to need to break out the volt/ohm meter and go to town testing. Really need to prove or disprove the 0V cranking reading on the screen. This will also allow you to test the alternator output and the ProCharge ACR.

[talltigeguy]

I might also add that a battery virtually never goes from functioning to 0V. Someone with more experience might chime in, but the deadest battery I have seen was still at 2V. The only way it gets to 0V is if something shorts out or becomes disconnected.