Alternator not charging. Is it safe to use the engine for daysailing

[Muttondressedaslamb]

I have owned a 2003 Catalina 310, equipped with the OEM Universal M25XPB diesel engine which is a converted Kubota farm tractor unit. That engine has always been a royal P.I.A. since I have owned the boat. This season, I have noticed that the voltmeter reading doesn't go above 12 volts, even with the engine at full throttle, suggesting a faulty alternator. The engine starts up and runs fine. Due to long covid, I am only daysailing this season and just need the engine to get me in and out of the harbor. Is it safe to use it this way, as long as I keep the 2 group 4d batteries charged up.

 

[kappykaplan]

Is it safe to use it this way, as long as I keep the 2 group 4d batteries charged up.

Should be . . .

 

[Muttondressedaslamb]

Should be . . .

Thanks for your prompt reply. It was the answer I kind of expected and definitely was hoping for. From what I understand, once diesel engine is running, it doesn't need electricity unless there is a fuel lift pump. My boat has one, but as long as the tank is above half full, it will run by gravity feed. Mutton Dressed as Lamb. It's what's for dinner

 

[Tally Ho]

Yes, it should be, but keep an eye on your voltage.

Maybe carry a battery pack to jump start the engine if you find you don’t have enough charge to start the engine. You should be OK, but we don’t know the condition of the batteries.

Greg

 

[Muttondressedaslamb]

Yes, it should be, but keep an eye on your voltage.

Maybe carry a battery pack to jump start the engine if you find you don’t have enough charge to start the engine. You should be OK, but we don’t know the condition of the batteries.

Greg

I already do carry a lithium ion jump starter

 

[Davidasailor26]

Even sitting at rest a battery should read closer to 13 volts than 12. You may want to use a multimeter to check your battery directly, both at rest and with the engine running, to confirm that your voltmeter is accurate. If it’s really under 12 keeping the jump pack available to start the engine if needed will be even more important.

I presume the M25 has a mechanical fuel stop cable, so you don’t need to rely on a powered solenoid for that?

 

[Muttondressedaslamb]

Even sitting at rest a battery should read closer to 13 volts than 12. You may want to use a multimeter to check your battery directly, both at rest and with the engine running, to confirm that your voltmeter is accurate. If it’s really under 12 keeping the jump pack available to start the engine if needed will be even more important.

I presume the M25 has a mechanical fuel stop cable, so you don’t need to rely on a powered solenoid for that?

it does have the cable. Maybe tomorrow I will drop anchor at my local Harbor Freight Tools and get a voltmeter. I trust my old pedestal mounted instruments as far as I can throw them

 

[Davidasailor26]

A digital multimeter is indispensable.

 

[Ralph Johnstone]

Follow all details as reported above.

I had to chime in here as I noticed you've changed your avitar and as always, in the finest of taste I might add.

Sorry to hear about your long covid. Take care of yourself and don't push it too hard.

 

[Muttondressedaslamb]

Follow all details as reported above.

I had to chime in here as I noticed you've changed your avitar and as always, in the finest of taste I might add.

Sorry to hear about your long covid. Take care of yourself and don't push it too hard.

Actually it is the same Avatar we talked about in private messaging. Maybe you forgot. I have not poked my nose on this site for a while. Thanks for your concern about my wellbeing

 

[Ralph Johnstone]

Maybe you forgot.

Forgot ? Huh ? I can't even remember what I had for breakfast half the time. Oh, that's right, Haven't even had breakfast yet.

 

[Muttondressedaslamb]

Forgot ? Huh ? I can't even remember what I had for breakfast half the time. Oh, that's right, Haven't even had breakfast yet.

Don't remember what you ate? Fire the chef

 

[odaydokay]

I am sure this is needless, but is your alternator belt decently tight?

 

[Muttondressedaslamb]

As tight as my wallet when my wife walks into a jewelry store

 

[dlochner]

Maybe tomorrow I will drop anchor at my local Harbor Freight Tools and get a voltmeter.

An accurate and reliable digital voltmeter is a useful tool. I'm not sure you'll find one that meets that criteria at HF.

 

[NYSail]

As tight as my wallet when my wife walks into a jewelry store

don’t make it too tight, you could damage the bearings on your water pump (coolant).

Greg

 

[east coaster]

Have a 2002 310, same engine and alternator. The voltmeter on the engine panel under reads by as much as 1-2 volts when compared against the readings on the Blue seas blue tooth shunt and a blue seas multimeter. As long as I am aware of this I am fine and can quickly check for a more accurate reading.

 

[capta]

No biggie if you can't start your engine to go back to your slip. That's how we all learned to sail our boats into and/or out of a marina.

 

[Tally Ho]

Have a 2002 310, same engine and alternator. The voltmeter on the engine panel under reads by as much as 1-2 volts when compared against the readings on the Blue seas blue tooth shunt and a blue seas multimeter. As long as I am aware of this I am fine and can quickly check for a more accurate reading.

My voltage at the helm is always less than on my electrical panel monitor, or a direct read from the battery with a DVM. I am always careful to watch the voltage, but I know 12.3v at the the helm is 12.5v at the monitor.

Yesterday, I finally got around to installing a “reserve” battery as my #2 battery on the battery selector. I have been running on my 2) 6-volt golfcart battery house bank for 2 years. While they are plenty to start my little Yanmar 2GM20F, I was always worried about being on the hook for a weekend sail, with a fridge on, and at some point not having enough juice to start the engine.

Now, with the group 24 reserve battery, I will not be so inclined to shut all of the lights off, turn off the fridge overnight, etc. The reserve battery is really only for “starting” emergencies.

Greg

 

[Muttondressedaslamb]

No biggie if you can't start your engine to go back to your slip. That's how we all learned to sail our boats into and/or out of a marina.

My boat is on a mooring, not a slip. I do practice sailing up to the mooring on a regular basis, leaving the engine running in neutral.