Starting problems 2004 Yanmar 3gm30f

[Tortuga331]

Hello,
The other day I went sailing. It started fine. I motored for 20 min to work the engine before sailing. After 2 hours of sailing, engine would not start.
I got towed in and plugged into shore power, after 2 minutes , it started right up. I figured it had to be batteries, so I bought 3 new batteries. I noticed when I started it up,after new batteries were installed, Red light saying "Charging" lit up and did not go off like usual after starting. I don't know if I have a bad charging system , bad alternator or possibly starter? How would I go about checking these things? BTW I called 3 mechanics , they are booked solid.
I would appreciate some comments, You all helped me so much in the past by Diagnosing my LIFT PUMP that went last year.

thanks all,
Bill
Tortuga

[Wotname]

While you may have more than one problem, let's deal with the charging light issue as that is definitely a known and significant problem.

The red light is telling you the alternator is not charging.

I assuming you have the standard stock Hitachi internally regulated alternator and you have checked the V belt is OK and tight etc. Check the wire and terminals on the alternator for security and corrosion.

To confirm the lack of charge, measure the battery voltage with engine OFF and all other charging sources are OFF (solar / wind / shore power / etc). It should be around 12.5 to 13V. Start the engine, increase RPM to more than 1,000 and check the battery voltage again, if it has not increased to around 14V, the alternator is faulty.

Remove and either have it repaired or replaced.

[Tin Tin]

Start with simple thing first, check the play in the V belt, it could be too loose and it may need a new belt and/or adjustment. It is detailed in the engine manual.

[Wotname]

Given your fault description, it sounds like the alternator hasn't been charging for some time and the start battery was old but without knowing your existing battery arrangements, switching and load distribution, it is hard to be definitive.

What were the exact symptoms when the engine failed to restart?

Slow / hesitant to turnover?
No engine rotation at all?
Only clicking of the start solenoid?
No sounds at all?
Normal starting rotation but engine failed to fire?
Engine stop cable in normal position (i.e. run)?

If engine has slow to turnover and fire, did you try using the decompression levers to aid starting?

[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

[Tin Tin]

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

This might help :

https://www.youtube.com/watch?v=T2nmWplQYXw

[Wotname]

Originally Posted by Tortuga331

.......... 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

Bill, I hear you and it can be frustrating. You have described the classic older Yanmar harness issues re starting. While the video that Tin Tin posted upthread is full of good advice, if it is beyond your expertise then isn't all that helpful for you.

First - save your money regarding a new starter; that will not be the problem.
Second - Get the alternator charging sorted out - probably best to either get it repaired if there are any auto electrical repairers in your area or just get a new one.
Third - Fix the starting issue (it is a separate issue to the alternator)...you don't have to have a great deal of expertise to do a simple fix which I will describe below. The fitting of another relay etc is a good fix but you got to have some basic electrical knowledge to do it properly so let's leave that aside.

Simple fix - Physically fit the new push button switch if you already have it otherwise see further below for another switch.

1. Connect the existing short white that goes between the Key Switch and the Start Switch

2. Discard the existing long white wire that goes toward the starter motor and disconnect it at the Starter Motor end as well.

3. Run a new 10 or 12 gauge wire directly from the instrument panel to the engine bay. Don't worry about any the the existing interconnections, by pass them all. The idea is to have a new wire going from the Instrument Panel (Start Switch) directly to the engine bay (Starter Motor). The colour doesn't matter although red is nice. I have shown this new wire in red on the diagram attached.

4 Connect the new wire to the Start Switch and to the Starter Motor. The right terminals are obvious (they were where the old white wire was previously connected to).

5. Turn Key Switch ON, press Start Switch and the engine will start first time, every time. If not, come back to this thread and get more instructions.

If you don't have the tools to make these simple terminations, now is the time to get then. The tooling, wire and terminals will be far cheaper and quicker than getting a mechanic to do the work. There are plenty of instructions everywhere on the web on how to make simple crimped terminations. Physically running and securing the new wire will be the hardest part. If access is difficult, find a young person to help run the wire between the panel and engine

If you don't already have the new Start Switch, get any after market push button momentary action that is good for say 15 Amps. Blue Seas sell a fancy one https://www.bluesea.com/products/418...h_OFF-%5BON%5D and there is no need to worry about the LED functions unless you want to. Just use the Red and Orange 16 AWG wires. The Orange wire will go to the Key Switch and the Red to the Starter motor.

FWIW, a momentary push ON switch will be described as OFF-(ON). The order of the terms and the brackets are important!

If you can hoist the sails, trim them to sail OK, navigate enough to get to and from the berth for a day, then you have enough smarts to learn how to carry out simple wiring repairs - you just need clear instructions to get you started.

If anything is unclear, just ask for clarification.

[Sos]

This is great info - having 2 number 3GM30's I am going to save this so hopefully I won't need it

[NYSail]

A real simple check is to jump the starter next time it happens. That will narrow the issue to the harness immediately. A relay is an easy diy project…… I did it on my last yanmar after having the itentical issue you are having starting. Prior to the relay, o would just jump the started bypassing the switch.
Good luck

[Tortuga331]

Thanks for your responses!
I have ordered 100 ft of 10 g marine grade wire. Should I run the wire from starter button to starter AND from key switch to starter as in the You tube video? OR, will the one wire be ok?
ALSO: I am ready to order an alternator, but I'm not sure if the one I order will fit the pulleys etc. If I remove it and get it restored, I know it will fit, but that might take a while.

thanks,
Bill
Tortuga

[chris mac]

Originally Posted by Tortuga331

Thanks for your responses!

I have ordered 100 ft of 10 g marine grade wire. Should I run the wire from starter button to starter AND from key switch to starter as in the You tube video? OR, will the one wire be ok?

ALSO: I am ready to order an alternator, but I'm not sure if the one I order will fit the pulleys etc. If I remove it and get it restored, I know it will fit, but that might take a while.



thanks,

Bill

Tortuga

I have the 3gm30's as well.
For the alternator, I ordered off Amazon and they worked perfect. The only issue was the pulley. I needed to swap with the old alternator so the belt width was right.
It was easy to do, took five minutes

[Tortuga331]

Originally Posted by chris mac

I have the 3gm30's as well.
For the alternator, I ordered off Amazon and they worked perfect. The only issue was the pulley. I needed to swap with the old alternator so the belt width was right.
It was easy to do, took five minutes

You are able to take the pulley off the old alternator?

[Tortuga331]

Originally Posted by chris mac

I have the 3gm30's as well.
For the alternator, I ordered off Amazon and they worked perfect. The only issue was the pulley. I needed to swap with the old alternator so the belt width was right.
It was easy to do, took five minutes

I looked on Amazon for an alternator, I saw ones that said 3gm30 but not 3gm30f. Which model did you buy?

Bill

[chris mac]

Originally Posted by Tortuga331

You are able to take the pulley off the old alternator?

Yes, I can't remember the socket size but using an impact driver while holding the pulley with a rag worked quite easy. Same with remounting.

[Wotname]

Originally Posted by Tortuga331

Thanks for your responses!
I have ordered 100 ft of 10 g marine grade wire. Should I run the wire from starter button to starter AND from key switch to starter as in the You tube video? OR, will the one wire be ok?
ALSO: I am ready to order an alternator, but I'm not sure if the one I order will fit the pulleys etc. If I remove it and get it restored, I know it will fit, but that might take a while.

thanks,
Bill
Tortuga

Yes, replace both wires as per the YouTube video upthread. I misled you in my previous post - my apologies for doing so. I had mistaken the video for a similar one where the video shows the fitting of a relay in the engine bay and leaving the existing wire in situ to operate the relay (the relay then operates the starter motor solenoid); I should have taken more attention - my bad.