I have a Hunter 340 w/ a yanmar 3gm30f. Yr built is 2000. I have had the standard intermitent starting issue for yrs which was confined to pushing starter button and not turning over. Now I turn the key and nothing happens. I have a seperate ignition key and none of the electrical works at the helm. I have replaced both the button and the ignition key switch. There is battery power to thenew key switch and volt meter reads 12.6 at connection until I turn the key switch on then volt meter goes all over the place. There is battery power to my electrical panel in cabin and at the engine. I can start engine with screwdriver at the engine and without key alternator is not charging batteries Does anyone know where I should check next? Am I killing my alternator by running engine with the key not on? I am on a mooring so I am obviouslly gonna be dreaining my batteries
No Electircal Power at the helm
- Thread starter beautifulday
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I would check the plug between the pannel and the motor as the pins get funky over time and work from there once your sure its good OR bad
We have different boats but Yanmar supplies both the motor, and the wiring loom for the motor, to all manufacturers.
From the Yanmar 3GM30 manual, here is how the power runs for the start circuit:
From the battery positive to the battery switch;
From the battery switch to the starter (fat red wire);
From the starter terminal with the battery lead, through an inline 30 amp fuse, to the key switch (red wire);
From the key switch, via a short white jumper wire, to the push button switch;
And finally from the push button switch, via a white wire, back to the starter solenoid terminal.
Boat wiring is generally stranded vs. solid. Wire will carry enough current and show voltage if only one strand is intact and the other strands are broken. This would allow you to get a voltage reading at the key switch but not enough intact wire to allow sufficient current to “power” the circuit. I suspect that you have a break (all but a strand or two) in the wire that runs from the starter to the key switch. It could also be a partially failed 30 amp inline fuse.
As a simple test, run a length of 12 gage wire direct from the battery positive to the red terminal on the key switch. This will isolate the feed side of the circuit. If your problem goes away, then you know where to look.
OK … Here is the “intermittent no start” problem. The “white” wire that goes from the push button switch to the starter solenoid is, at best, marginally adequate to feed the current needed to energize the starter solenoid when the boat is new. The circuit naturally develops internal resistance with age. This increased internal resistance, combined with undersized wire, reduces the current flow through the white wire. The result … When the starter starts to turn, the current draw causes a voltage drop just big enough to disengage the starter solenoid.
A number of us Beneteau owners have installed a Ford style automotive starter relay to eliminate the problem. The white wire just triggers the relay vs. powering and holding the starter solenoid closed when the starter cranks.
From the Yanmar 3GM30 manual, here is how the power runs for the start circuit:
From the battery positive to the battery switch;
From the battery switch to the starter (fat red wire);
From the starter terminal with the battery lead, through an inline 30 amp fuse, to the key switch (red wire);
From the key switch, via a short white jumper wire, to the push button switch;
And finally from the push button switch, via a white wire, back to the starter solenoid terminal.
Boat wiring is generally stranded vs. solid. Wire will carry enough current and show voltage if only one strand is intact and the other strands are broken. This would allow you to get a voltage reading at the key switch but not enough intact wire to allow sufficient current to “power” the circuit. I suspect that you have a break (all but a strand or two) in the wire that runs from the starter to the key switch. It could also be a partially failed 30 amp inline fuse.
As a simple test, run a length of 12 gage wire direct from the battery positive to the red terminal on the key switch. This will isolate the feed side of the circuit. If your problem goes away, then you know where to look.
OK … Here is the “intermittent no start” problem. The “white” wire that goes from the push button switch to the starter solenoid is, at best, marginally adequate to feed the current needed to energize the starter solenoid when the boat is new. The circuit naturally develops internal resistance with age. This increased internal resistance, combined with undersized wire, reduces the current flow through the white wire. The result … When the starter starts to turn, the current draw causes a voltage drop just big enough to disengage the starter solenoid.
A number of us Beneteau owners have installed a Ford style automotive starter relay to eliminate the problem. The white wire just triggers the relay vs. powering and holding the starter solenoid closed when the starter cranks.
Helm Power
I agree with Paul.. here is what I think is your wiring schematic.. I was looking for it earlier .. finally found it
If you search this forum using "yanmar hard start" I think you'll find the relay mod including part numbers and a diagram..
The long rectangles in the diagram are the multi pin connectors that probably could use some cleaning..
I agree with Paul.. here is what I think is your wiring schematic.. I was looking for it earlier .. finally found it
If you search this forum using "yanmar hard start" I think you'll find the relay mod including part numbers and a diagram..
The long rectangles in the diagram are the multi pin connectors that probably could use some cleaning..
You may want to try running a temp wire from the key switch to the starter and see if you get her to start. If that works, you may be able to purchase a complete wire harness from Hunter or have one built.
The new wires normally eliminates the need for a relay.
Be sure to check out all the connects before you do anything else.
The new wires normally eliminates the need for a relay.
Be sure to check out all the connects before you do anything else.
If you just replace ALL the motor loom connectors with soldered connections the problem goes away.
there are around 11 connections between the battery + term and - term in the starter solenoid circuit. No less than 6 of them are motor loom connectors that you really do not even need. They are there so the manufacturer can install the motor easily. Unless you replace your motor regularly you do not need the motor to boat loom connectors. when I cut out the connectors and hard wired them I also notice changes in the temp meter, RPM and oil pressure meters. They all suffer when the wires have more resistance (corroded connectors) than when new.
there are around 11 connections between the battery + term and - term in the starter solenoid circuit. No less than 6 of them are motor loom connectors that you really do not even need. They are there so the manufacturer can install the motor easily. Unless you replace your motor regularly you do not need the motor to boat loom connectors. when I cut out the connectors and hard wired them I also notice changes in the temp meter, RPM and oil pressure meters. They all suffer when the wires have more resistance (corroded connectors) than when new.
Hunter 340 starting issue
Thanks for the help everyone. If I run a temp wire from starter to key to test what size wire? 12gauge? Same as wire i run from battery to key? Can I try starting engine with both these tests if the other stuff at helm starts working? Worked on it yesterday and had enough power to get the tac, alarm etc working. had to hot wire engine to turn over but key was on and tested batteries w engine running and they were charging. volt meter showed 13.8 w engine running at 1400rpms. but turned engine off and helm lost power again. If it works can I use any of these temp fixes until boat pulled in fall? esp since i wiring directly so wouldnt be usiing fuse
Thanks for the help everyone. If I run a temp wire from starter to key to test what size wire? 12gauge? Same as wire i run from battery to key? Can I try starting engine with both these tests if the other stuff at helm starts working? Worked on it yesterday and had enough power to get the tac, alarm etc working. had to hot wire engine to turn over but key was on and tested batteries w engine running and they were charging. volt meter showed 13.8 w engine running at 1400rpms. but turned engine off and helm lost power again. If it works can I use any of these temp fixes until boat pulled in fall? esp since i wiring directly so wouldnt be usiing fuse
Tested and replaced the wire from fuse near starter to key post and everything including starting engine worked better than it has in the five years Ive ownwd the boat. Thank you soooo much
Beautifulday........I have had the same problem with my defective yanmar harness also. After it finally burned up my starter from not being able to pull the right amps to it. First thing I did was traced down every hidden defective connector on the harness. At each and every connector I burnished the contact points and then used a small screw driver on the contact pins making the connections has tight as possible. I then coated all contact surfaces with a dielectric grease before plugging them back together. I then ran a continuous #10 white wire along harness from instrument panel white momentary wire at key or momentary start button (my solid brass key switch also as a monentary position) Then to same location were original white wire connects at starter. Left original wire in place.
Now she kicks over first try with no sweet!
I also did a few other improvement while I was at it. Like a dedicated startbutton,1/both/2/off selector switch all next to engine. #1 to reserve/starter battery #2 to house bank , echo charger to reserve/starter battery. This way I no longer have to have leave power to starter battery live 24/7. When getting ready to start engine. Open engine compart do quick inspection before starting motor. Then switch selector switch from off to #2 to house bank this way alternator sees only house bank for proper charging. Echo is connected to #1 on isolator which then goes directly to alternator. #2 on isolator goes directly to house bank. Alternator always has a path way to send juice somewhere. When back home and done for the day open engine compartment inspect engine and shut off power to starter. Fantastic setup!
Now she kicks over first try with no sweet!
I also did a few other improvement while I was at it. Like a dedicated startbutton,1/both/2/off selector switch all next to engine. #1 to reserve/starter battery #2 to house bank , echo charger to reserve/starter battery. This way I no longer have to have leave power to starter battery live 24/7. When getting ready to start engine. Open engine compart do quick inspection before starting motor. Then switch selector switch from off to #2 to house bank this way alternator sees only house bank for proper charging. Echo is connected to #1 on isolator which then goes directly to alternator. #2 on isolator goes directly to house bank. Alternator always has a path way to send juice somewhere. When back home and done for the day open engine compartment inspect engine and shut off power to starter. Fantastic setup!
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