Starting problems 2004 Yanmar 3gm30f

[Capt.Don]

Geoff,
Our boat is a 2000 Tartan 3500. I'm certain the previous owner upgraded the electrical and replaced the alternator since I have the original 35a (possibly 50a?) as a spare. I'm still finding remnants of various wiring iterations as I upgrade and replace components.
Don

[Cheechako]

Originally Posted by Geoff54

Hi Don - Just for curiosity, what boat is this?

AFAIK, Hitachi supplies electrical components to Yanmar.... BUT Yanmar is willing to supply engines without certain components. As an example, Catalina tend to use custom instruments, rather than the Yanmar panel, This also means the the usual Yanmar temp. sender does not work properly (different resistance) and the usual instrument sender has the wrong thread for the engine, so there is a Catalina specific sender.

I wonder if your alternator might be boat manufacturer specific. Either that or I suspect a previous owner installed it.

As I said, just curious.

Geoff

Yeah, there's little doubt that's not a factory alternator.

[Geoff54]

Originally Posted by Capt.Don

Geoff,
Our boat is a 2000 Tartan 3500. I'm certain the previous owner upgraded the electrical and replaced the alternator since I have the original 35a (possibly 50a?) as a spare. I'm still finding remnants of various wiring iterations as I upgrade and replace components.
Don

Thant makes perfect sense. Thank you!

[Tortuga331]

I just dropped off my alternator and starter to be rebuilt,
I'm afraid to buy any new things that may not be as robust as the original part.
I found a guy who fixes all the yanmar tractors in the area. This way I know the part will go back in and will fit. In a week I will reinstall and give an update.

????? Does anyone know the name of a little plastic white piece that inserts into the back of the alternator? I think it connects to the wire that goes to the NOT CHARGING LIGHT on the instrument panel.???????

Bill
Tortuga

[flightlead404]

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

my yanmar will occasionally not start due to a little corrosion on the fast-on 1/4" terminal for the ground wire on the starter. A little cleaning and its fine.

my yanmar does not use a relay in the starter enable circuit so that means the full current to close the big starter solenoid has to travel all the way to the key switch and back. I really need to put a relay in that circuit.

[Tortuga331]

Originally Posted by flightlead404

my yanmar will occasionally not start due to a little corrosion on the fast-on 1/4" terminal for the ground wire on the starter. A little cleaning and its fine.

my yanmar does not use a relay in the starter enable circuit so that means the full current to close the big starter solenoid has to travel all the way to the key switch and back. I really need to put a relay in that circuit.

I heard of 1) relays to solve the problem,
2) I have heard of using 10 gauge tinned wire to rewire from the starter button to starter and back.

Anyone have any comments pos or neg on which way to go?

[flightlead404]

Originally Posted by Tortuga331

I heard of 1) relays to solve the problem,
2) I have heard of using 10 gauge tinned wire to rewire from the starter button to starter and back.

Anyone have any comments pos or neg on which way to go?

Those are not mutually exclusive.

[Wotname]

Originally Posted by Tortuga331

.........

????? Does anyone know the name of a little plastic white piece that inserts into the back of the alternator? I think it connects to the wire that goes to the NOT CHARGING LIGHT on the instrument panel.???????

Bill
Tortuga

Presumably you mean the small T shaped connector that has houses two spade terminals. If so, both wires are essential otherwise the alternator will not charge.

The L terminal (Blue/Black) goes to the charge light; L=light
The R terminal (Red/Black) goes to the load side of the Key switch. R=regulation

The L also provides the initial field voltage (via the charge light) when the alternator first spins up. Once the alternator rpm becomes self exciting, no further current flows via the charge light thus it is extinguished.

The R terminal is the sense wire for the internal regulator.

While the plastic housing is not essential as the terminals are just normal push on spade terminals, it is handy as it ensures both wires are connected to the correct places. I have never tried to buy the housing but I guess they are available at any auto electrical shop etc.

[Wotname]

Originally Posted by Tortuga331

I heard of 1) relays to solve the problem,
2) I have heard of using 10 gauge tinned wire to rewire from the starter button to starter and back.

Anyone have any comments pos or neg on which way to go?

1 (using a relay). Pro - You don't have to access the rear of the panel. You don't have to run wires from the panel to the engine bay which can be difficult in some instances; Con - You are relying on the existing degraded wiring / corroded interconnects to power the relay (kicking the can down the road). You are adding another component (the relay) which may fail. You have to physically fit, provide a power source and connect the relay in the engine bay.

2 (using 10AWG wire). Pro - simple and no additional components required. Con - Access to run the wiring and the rear of the panel can be difficult in some instances. You are bypassing the interconnect plugs in the original Yanmar harness.

At the end of the day, either will work and it often depends on access and the electrical capability (expertise) of the guy doing the work.

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

[RaymondR]

On both my boats I have put a starter button in or near the engine enclosure, handy to have if the key start doesn't work or you need to crank the engine to bleed the fuel system.

[Tortuga331]

Originally Posted by Wotname

1 (using a relay). Pro - You don't have to access the rear of the panel. You don't have to run wires from the panel to the engine bay which can be difficult in some instances; Con - You are relying on the existing degraded wiring / corroded interconnects to power the relay (kicking the can down the road). You are adding another component (the relay) which may fail. You have to physically fit, provide a power source and connect the relay in the engine bay.

2 (using 10AWG wire). Pro - simple and no additional components required. Con - Access to run the wiring and the rear of the panel can be difficult in some instances. You are bypassing the interconnect plugs in the original Yanmar harness.

At the end of the day, either will work and it often depends on access and the electrical capability (expertise) of the guy doing the work.

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

Where would a power source come from for the relay?
It seems to me the rewiring w 10 g is the best option and I will attempt to do that.

Bill
Tortuga

[Tortuga331]

Originally Posted by flightlead404

my yanmar will occasionally not start due to a little corrosion on the fast-on 1/4" terminal for the ground wire on the starter. A little cleaning and its fine.

my yanmar does not use a relay in the starter enable circuit so that means the full current to close the big starter solenoid has to travel all the way to the key switch and back. I really need to put a relay in that circuit.

So, current flows from starter to key swicth and back.
I thought from start button to starter or ignition to starter ?

Bill
Tortuga

[sinnerman]

Right after I bought my boat (Catalina 30) it would not start. (Not a Yanmar, but still a diesel).

I cleaned up the rats nest of wiring on the engine and installed a new harness from the cockpit start/instrument panel to the engine.

Catalina used to have an amp meter on the panel to show the alternator current but this was a fiasco as ALL of the current form the alternator to the battery/boat systems had to now pass through the cockpit. Ammeter was removed and a voltmeter installed in its place.

The original design also utilized a trailer hitch type connector which would corrode and cause intermittent / heat generating connections (think electrical fire).

My alternator was not working as well and the diodes had corroded so badly they were broken off. An alternator shop rebuilt the unit including a new regulator for about $150.

I would replace the start battery with a new one as it has not been properly charging for a while and is probably shot. Batteries only last a few years before needing replacement.

I do not see the need for a relay for the start solenoid as the solenoid draws little power and should work fine if the harness is healthy. I DID install a relay however for the glow plugs as again the current (VERY high amperage) had to travel to the cockpit and back. Putting a relay near the engine for the glow plugs made sense.

My two cents

cheers

[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.

[JBsurfin]

Originally Posted by 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

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?