Volt, ampmeter and tack dead

[FULLCIRCLE331]

VOLVO MD203O
Returning from Greenport Saturday my charging system stated acting up. At first the charging amp-meter showed no out put and the battery alarm came on. I paralleled the starting system with the house system since the house system is much larger and has solar charging. I figured this would allow me to get home running the injectors. A little latter the amp, voltage meters and tacometer started to pulse. The battery voltage was maintained all the way home. After shutting down the engine at the mooring the house batteries were at 14.2 volts and the starting battery 13.2 which it normal for my system. I believe that the charging system was charging. I have a battery isolator the separates the two systems, is it possible the one side of the isolator went bad.

Today Tuesday I started the engine, all three meters stayed at zero. The starting battery is at 12 volts.

Any ideas or suggestions before I start checking thing out. That probable wont be until Thursday.

[belizesailor]

What kind of regulator are you running? Its common for smart regulators to sometimes cause similar symptoms when the batteries reach full charge and it shuts down output from the alternators.

[FULLCIRCLE331]

I have a Volvo isolator that distribues the charge to 2 4D house batteries and the starting battery. House batteries are charged with solar all ways at full charge. Monday the charging battery was at 12 volts all metters still dead. The altenator is new. at he end of last season ammeter was dead. New altenator start of this season all looked good. At less than 10 hours thingswent bad. I just took the old altenator apart. The insolator on the + terminal was broken and appears to have shorted out, some plastic is melted.

[belizesailor]

So I assume the alternators are internally regulated?

If so, plus the damage you've found then likely another problem (not an external smart regulator issue).

Sounds like maybe a short or high voltage (usually a regulator issue) cooked some wiring and guages. I would test the gauges to see if they are toasted or just not getting juice to them and work backwards from there.

Take solar offline and then test alternator for output with a multimeter.

Inspect/test positive circuit from alternator to batteries for a short. A ground fault somewhere along the circuit could have caused big amp draw and cooked the terminal and gauges. That circuit should be fused if it is not to prevent a boat fire.

[FULLCIRCLE331]

Today I got to the boat to start work. First just started the engin, all meters still dead. checked altenator out put, 4 volts, but batteries fully charged. As suggested by several people suggested I disconnected the solar and turned on enough things to draw 10 amps for a few minutes. Restarted the engin and all meters worked. It appears the house batteries were over charged stopping the regutator from charging.

Thanks to all for their help.