Voltage Question

Squid1962

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I have a 2008 330 express with 350s. The 350s have new heads. I noticed this am the port engine runs at 14.2v and the stbd runs at 13,0-13.4.v. Thoughts?
 

seasick

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Does each motor use a different starting battery? I think they would have to.
Assuming the batteries are in good shape AND charged, I would expect similar charging voltages ( idle speed voltages might be different a bit)
Are the voltages different by the same amount after the motors warm up?
Either way, unless one motor's battery has much heavier load on it, the voltages should be close.
Do you have a shore powered charger running and if so, when you first get on the boat after sitting for a whilw ( day oy a few days) what does the charger indicate.

If for what ever reason the bilge pump is cycling or worse and you do not have a charger connected and operating, the batter that the bilge pump runs off of may be getting run down.

Worst case, there is a problem with the engine that only makes 13 volts.
 

wspitler

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See the same thing on my 2007 330. The voltage regulators are computerized and provide voltage based on battery bank state. Mine often start at 13.4 and build up to 14. After some time running and the battery is being topped off they will drop back down to 13.2 which is maintenance charge. Normal. Don’t worry about it.
 

ElyseM

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cannot specifically remember the voltage, but i believe my '09 F350s maxed at 13.6v. the more load the lower the voltage. discussion with tech indicated the F350's were built that way. they don't spin up. maybe one of yours also received an updated alternator.

Current F300's are pumping out 14.4v.

hope this helps. good luck, ron
 

seasick

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It is difficult to say is something is amiss without knowing the standing voltages of the batteries. That is the voltage measured at the battery terminals with a meter and all loads switched off. Normally, if they are the same for bank 1 and bank 2, I would expect the voltage reported by the motors to be about the same after starting the motors, letting them warm up and raising the revs to 1200 or so.
 

Hookup1

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There are lots of posts here about this issue. Start off simple. If you are not getting proper voltage reading check the charger fuses.

As others have said get a inexpensive voltmeter (Harbor Freight). Measure voltage at the batteries.
Battery switches set to each engine.
Charger off. motors off. Check voltage. Should be 12.8 vdc.
Charger on. motors off. Check voltage. Should be 13.1 vdc.
Charger off. motors on. Check voltage. Should be 13.1 vdc.

You need to be careful using the Garmin unit to measure voltages. I have found the voltage on the sounder display to read low (house battery). The engine gauges, if you are setup that way, tend to read correctly.

House battery charging is a little different. Ideally you have a 3rd-bank charger and one motor wired properly to charge 3rd-bank.
Charger off. motors off. Check voltage. Should be 12.8 vdc.
Charger on. motors off. Check voltage. Should be 13.1 vdc.
Charger off. motors on. Check voltage. Should be 13.1 vdc. Assuming you have a charging shunt from one of the motors.

If the batteries are discharged it may take a while (overnight) to bring them to a full charge. There are usually fuses on the individual charger cables as well as on your engines. The voltmeter will tell you what's charging and what's not.
 

drbatts

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Not sure of your exact battery setup however. If you have a 2 bank setup and the starboard bank is for engines and house. If you are running anything on the 12v side I.e. radio,fridge, electronics. Then this draw may account for the lower voltage.