[C38] Electrical System Troubleshooting

[Charles Finn]

Jay,

I could be wrong on this, but it sounds like a bad ground.  The 
batteries are grounded to the engine and the ground is usually low on 
the port side.  Corrosion is the most likely culprit and it is easy to 
see why this might be your problem in salt water.   Best way to test 
this is to run a jumper cord from the negative side of your battery to 
the engine mount.  Corrosion is enough to stop small drains while 
allowing the starter to run.

Hope this helps!
Chuck Finn
Mighty Quinn #114
Lake Superior

On 1/22/2019 10:47 AM, Jay Sorensen wrote:
> G'Day All,
>
> We've owned Broad Reach, a 1985 C38 with a fairly standard electrical 
> system for about 6 years.  I've diagnosed several electrical issues to 
> date but this one is something a little different.  I replaced our 
> aging starting battery with an AGM group 24 battery on Saturday.  
> During our outing on Sunday our engine started fine with Battery #1 
> (AGM starting battery), but when attempting to turn on any system via 
> the panel there was no power.  Try battery #2, no power.  Try "Both", 
> no power.  Check the battery voltage using the panel voltmeter, no 
> power shown at the voltmeter while the engine was running. Come back 
> to the dock, stop the engine, voltmeter shows 12+ volts power at the 
> panel from both batteries at the voltmeter.  With shore power on the 
> panel will power up when jumping to the battery charger cables running 
> to the battery switch.  Panel will not power up when powered directly 
> to either main battery cable.  Battery cables showing 0.1-0.2 Ohms of 
> resistance but I'm not sure if that is normal.  Turned off shore 
> power, started motor again with switch to #1, started fine, alternator 
> is charging fine.  Weird.  Next I'll try jumping directly to the 
> batteries and bypass the cables but it seems odd that both cables are 
> having issues when they show good voltage.  Frustrating!  Any 
> suggestions??  Maybe something where the engine electrical system 
> interacts with the system power panel inputs??  Many 
> Thanks!...............Jay
>
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