Battery isolator switch and low voltage

[coachbrandt]

I have a 2008 z1 with a 5.7 vortec, my voltage gauge is only reading 12.1 when the boat is running. I had the alternator off and checked and it is putting out 14.1 - 14.3 so that is good, my readings coming out of the isolator switch is just over 12 on each side (each battery). Does anyone know anything about the isolator switches, do they go bad, how many volts should I be getting coming out of the switch. I have a two battery system with an on/off switch. It is a Charles industries isolator switch.



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[chpthril]

if the voltage on each side of the switch, were the same, then the switch is good.

my readings coming out of the isolator switch is just over 12 on each side (each battery).

Checking at the switch only tests the main cranking battery. Was this reading with engine running or off? What was the actual reading? 12 point what?

Have you tested the voltage at each battery with engine off and running?

my voltage gauge is only reading 12.1 when the boat is running

This helm reading is of the house battery, which could easily be dead/bad/expired or not completely connected.

[coachbrandt]

12.1 and 12.3 were the actual readings I don't remember what reading was on which side and that was with the engine running


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[chpthril]

Those numbers indicate that there is no alternator charge reaching the batteries. My 1st guess would be to confirm that the main ground is connected to at least on of the batteries. Next, I would find the 3-wire isolater and touch the meter's B+ lead to the center post (should see alternator voltage with engine running), then the two outer posts (they should be about .7V less than the center post. Next, fallow those outer posts cables to the batteries to make sure they are each connected to one of the batteries.

[coachbrandt]

Ok, thanks for the info will be a while before I try this as in storage but gives me something to try


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