Starting problems 2004 Yanmar 3gm30f

[Tortuga331]

Originally Posted by JBsurfin

I've yet to see a battery come off the shelf fully charged. Did you try charging first for an hour or so, then start?

You are right, they were not fully charged! However it seems that I have several issues going on. I am waiting for my starter and alternator to be rebuilt. I will be cleaning my negative terminals to the starter and alternator before re installing them, I will also run a 10 g wire from the start button to the starter and hope all my problems go away!

Bill
Tortuga

[Tortuga331]

Originally Posted by SuW

We had a different problem fwiw; the engine would turn over and start only with difficulty (A late 90s Yanmar 3GM30F). The issue was a lot worse in cold weather - it would rarely start at all.

We were up for a major refit. so we:

• moved the batteries 10 feet closer to the engine(!)
• put in a starter battery and large house bank with combiner
• rewired everything with larger gauge wiring
• renovated the cockpit engine panel which had been leaking rainwater
• had the alternator and starter tested (both were fine)

After all this, the issue was somewhat better, but what made starting completely reliable was to put the throttle on fully when starting, then throttle back as the engine started, which it does straight away.

What do you mean by " Somewhat better"?
You would think everything should be perfect with all the effort you put in.

[sinnerman]

As some of the commentators have stated, you really need to get your self a voltmeter.

They are cheap enough and you will need it for troubleshooting pretty much anything electrical on the boat.

Put the voltmeter across the start battery. Note the voltage before it starts and after the engine is running.

You can do the same using the house battery / batteries.

The voltage should be higher after the engine is running. Around 14 volts

If the voltage is higher with engine running the alternator is charging.

If it is not, problem could be alternator (including bad diodes), the alternator regulator or corroded/loose wiring.

cheers

[flightlead404]

Originally Posted by Wotname

As FL404 notes, you can do both; if so, the relay only needs light wiring (say 14AWG) from the panel to the engine bay.

Which I think is a pro. Also, just get a couple standard A type relays from an auto parts store and the proper base. I haven't had one of those fail in donkeys years, but they're like $8 so silly not to have a spare.

[Icarus]

Originally Posted by Tortuga331

The boat ,since I bought it , starts great on the first try, or does not start unless you try 3 or 4 times. I have had this boat for 3 years and always cringe after sailing ,hoping it will start. I heard about relays, rewiring , new starter , new start button etc etc.

I can not take people out and not know if it is going to start. So, I did order a new button, I will order a new alternator and starter. Any ideas on which company to order from? I want a very good quality part if possible.

When it doesn't start, it makes NO noise , no sound, nothing, nada.

BUT, if I pepper the button and press fast 5 times it usually does the trick, but not always. I have read that the engine may start well when you leave the dock and Not start after sailing because the resistance is increased somehow due to heating of the wires. I t a known problem that Yanmar used untined wires that now are creating more resistance and should be rewired with 10 g wire or put in a relay, This is all beyond my abilities. BUT, I will have to do something due to NO mechanics avaiable.

I just want to sail in peace and not worry.

thanks for your great advice.



Bill

Tortuga

Sounds like bad connections, check all wires a d terminal lugs....
Check starter motor relay..bad contacts, lose wires?

[GrowleyMonster]

A digital volt meter is absolutely essential. You NEED one and you need to learn all the cool things you can do with it. Very important. Figure on $30 to $60 for a bare bones but still useful one.

I am pretty sure you will get your charging problem sorted pretty quick once you have a meter and you can see when the alternator is charging, and how charged the batteries are. You also need to learn about batteries, along with electricity in general. Whoever told you that there wouldn't be any math, was lying. Get used to it! Learn about Ohm's Law, and how voltage, current, and resistance work with or against each other. Learn how to check your batteries' specific gravity and how to use a voltage reading. The voltage of a battery that has only just now been charged or discharged, will not tell you much.

Most setups do not really allow the alternator to charge until you are going significantly faster than idle speed.

First thing, make sure you have a good cable from battery to starter. Check the voltage between the big starter cable at the starter, and ground. Should be at least 12 volts, more if the batteries are fully charged. Next, disconnect that cable and measure its resistance. It should be only a couple of milli ohms.

Your starter is probably fine. You could have a weak or sticky solenoid, though. Usually, this is a small can looking thingie bolted to your starter. The solenoid is basically an electrically powered switch that uses an internal electromagnet to slam the contacts together and complete the starting circuit. It may also push the drive gear to engage it with the ring gear on your flywheel but usually not. What you want to do is bypass the solenoid and see if the starter motor kicks even when normal start attempts have failed. This will tell you something that you probably already know, that you have a good starter motor and enough juice in the batteries to start the engine and a good power cable and good connections. But it's all about eliminating parts of the circuit as possible malfunction points. You can jump across the solenoid power terminals with a screwdriver or whatever. Get a knowledgeable person to show you how. You might find a youtube vid showing how to do it, too.

Once you have failed to get a start with the normal switch but can get a start by jumping the power cable directly to the starter motor, you know that your starter power circuit is fine, but your control circuit is not. This is comprised of your switch, start relay if you have one, and any start disable switches that you might have, such as for water temp. You will need to draw out your circuit and isolate the components, food for another post.

Old mechanic trick I learned from an old mechanic. Tap on the solenoid with a wrench or screwdriver a few times. Sometimes they get weak, or stuck.

[Tortuga331]

Learn how to check your batteries' specific gravity and how to use a voltage reading. The voltage of a battery that has only just now been charged or discharged, will not tell you much.

Is there a specific tool you recommend to check specific gravity?

Bill
Tortuga

[GrowleyMonster]

Originally Posted by Tortuga331

Learn how to check your batteries' specific gravity and how to use a voltage reading. The voltage of a battery that has only just now been charged or discharged, will not tell you much.

Is there a specific tool you recommend to check specific gravity?

Bill
Tortuga

Yes. It is called a hydrometer. It utilizes a float that floats higher or lower according to the s.g. of the measured fluid. Here is a decent one.
https://www.amazon.com/OTC-4619-Prof...+tester&sr=8-7

The manufacturer of your batteries can tell you exactly what s.g. to expect at what temp and what state of charge, or vice versa. They should have a website with the data for the battery. I am assuming you have normal deep cycle FLA batteries.

[GrowleyMonster]

Here. Spend some more $. You will be glad you did.

Here's some books for you. Highly recommended.

https://www.amazon.com/12-Volt-Bible...t+bible&sr=8-1
This is a very good book on 12VDC marine electrical systems. If you spend the next few months studying this and practicing all the things that are even remotely practical, you will develop the skills and knowledge to troubleshoot, repair, modify, or upgrade any and every part of your boat's 12v setup.

https://www.amazon.com/Boatowners-Me...+manual&sr=8-1
If you buy only ONE book on diagnosing and fixing things on your boat, let this be it.

https://www.amazon.com/Marine-Diesel...+calder&sr=8-1
This book is a bit more hardcore but honestly you could take a pretty good stab at almost any engine repair if you learn this book cover to cover, even do an overhaul yourself. (and potentially save thousands of dollars!) For right now I would put this in the "nice to have" category but eventually you will probably want this, for more in depth knowledge about your engine than what is presented by the excellent and essential "Boatowners Mechanical and Electrical Manual".

[Tortuga331]

UPDATE:

I relaced my REBUILT starter and alternator. I also replaced the wire from ignition to starter with a 10 gauge tinned wire! It starts EVERY TIME so far on the first push of the button! All is well with Tortuga for now.
Thank you all for your help!

Bill Panek
Tortuga

[SV-Apres]

Originally Posted by Tortuga331

UPDATE:

I relaced my REBUILT starter and alternator. I also replaced the wire from ignition to starter with a 10 gauge tinned wire! It starts EVERY TIME so far on the first push of the button! All is well with Tortuga for now.
Thank you all for your help!

Bill Panek
Tortuga

Glad it worked for you. I rewired mine about a year and a half ago (and recoded the video referenced above). I have not had the issue since!!

Such a simple and effective fix.

[Wotname]

Originally Posted by Tortuga331

UPDATE:

I relaced my REBUILT starter and alternator. I also replaced the wire from ignition to starter with a 10 gauge tinned wire! It starts EVERY TIME so far on the first push of the button! All is well with Tortuga for now.
Thank you all for your help!

Bill Panek
Tortuga

Great news!

Did they find anything wrong with the alternator and is it charging OK now?

[jeffaronson]

many thanks for this. i am having a similar issue with my yammar (3jh2e 2000 vintage). it starts reliably at the dock. but when i turn the key on my way back to the dock --nothing. for 1 or (today) 2 attempts -- before starting. btw i do not have a button --just the key needed to start the engine....

[GrowleyMonster]

Originally Posted by jeffaronson

many thanks for this. i am having a similar issue with my yammar (3jh2e 2000 vintage). it starts reliably at the dock. but when i turn the key on my way back to the dock --nothing. for 1 or (today) 2 attempts -- before starting. btw i do not have a button --just the key needed to start the engine....

You don't necessariily need a start pushbutton if you have s start enabled key switch.

If I understant you connrectly, turning the key to the START position does not make the starter engage and turn the ring gear and so the engine does not get turned over. First thing to do IYAM is short across the starter solenoid with a big screwdriver or similar, and see if the engine turns over. If that happens then you know the starter is good though the solenoid is still not verified. If no joy, measure the voltage at the starter both statically and when starting. If your 12V starting battery of sufficient capacity is fully charged, you should see about 12.6VDC give or take a tenth, between hot and ground, which may be a cable going back to the battery, or might simply be the engine itself. Now test the voltage during a start attempt. You should see at least 11V at the starter. More is better. The energized starter pulls down the system voltage by drawing a LOT of current, and if you know your Ohm's Law math, you know that say a 10 foot run of cable with moderate resistance in the wire of its connections, causes a severe voltage drop.This can be caused by too small of wire, or bad connections, or tired old batteries. For a small and simple system, Size 0 gauge cable is treat and you could go as low as AWG2 cable. I prefer 2/0 welding cable because it is so easy to work with, but this is AFAIK not compliant with ABYC standards, just so you know. Don't go smaller than #2 gauge copper cable! Check all you connections. Check your batteries for proper electrolyte level and specific gravity if you have proper Flooded Lead Acid batteries. Again, check the voltage during a start attempt. Get a helper if you need one.

So once your primary system has checked out, time to look at the starting circuit. This is the circuit that energizes the coil of the solenoid which works like a remote switch to connect all that start current to the starter motor. The start circuit and/or run circuit might also have other functions such as runing an electric fuel boost pump or pre-lube or engine air preheater or glow plug.

So, pull the starter switch and check your contacts and connections. Contacts that are supposed to be closed should have almost zero resistance, on the order of a milli ohm or less. If not, spray with CRC and work the switch back and forth, try again. No joy? Replace the switch. Engine ought to start okay now.

You may have a start relay. If so, figure out the internal connections and try connecting 12V to the + coil contact by placing the switch in the START position

If that didn't work, hook the relay coil directly to the battery with a 12AWG wire for the positive, boa't's ground for the negative.If that didn't work, check the resistance of the start relay coil. It sould be somewhere between 100 milli ohms down to say 40 milli ohms. If resistance is zero, you got a short. If it is too high, you got an open. Either way it's toast. Eliminate the relay or get a new one.

So nothing made the engine kick over... okay you got one more hail mary play here. Check the starter solenoid. Measure the resistance of the coil. Should be under 60 milli ohms but certainly under twice that amount, but absolutely above nothing.

The entire start circuit is start switch, start relay and wires to it from start switch, starter solenoid and wires from start relay to start solenoid, connection between start solenoid and starter motor, Battery, cables from battery including all terminals, and the starter motor itself. If you have checked all of that, then maybe the engine is locked up. Roll the engine over by hand, using a breaker bar on the crankshaft nut or pulley nut. If there is a compression release lever, try to turn the engine over in both positions. Thoroughly secure the starter to some fixed object and hit the starter for just a blip. If engine is not seized and the starter spins up, it SHOULD start.

Things to check. Starter has some broken or shorted windings. Take your starter to a starter and alternator shop for diagnostics. There may be a circuit that inhibit start until oil pressure is above a certain level, for instance. People do lots of crazy wiring to complicate a simple diesel engine starting system.

[sinnerman]

Originally Posted by jeffaronson

many thanks for this. i am having a similar issue with my yammar (3jh2e 2000 vintage). it starts reliably at the dock. but when i turn the key on my way back to the dock --nothing. for 1 or (today) 2 attempts -- before starting. btw i do not have a button --just the key needed to start the engine....

If no "clicking noise" when trying to start:
- Bad wiring between panel and engine, and/or no power going to panel.
(check harness connectors if applicable)

If clicking noise when trying to start:
- Bad starter solenoid or starter. (you can get starters rebuilt at an automotive shop)
- Poor ground cable connection to engine (commonly neglected item...)
- Poor battery connection to starter (corrosion)

cheers