Need Yanmar 4JH3E Help Urgently

[Tom_F]

2004 Jeanneau 40.3 with Yanmar 4JH3E will not start. Start and house banks are isolated, house bank is18 month old AGMs start bat replaced 20 minutes ago. Had the ignition switch replaced in July by certified Yanmar mechanic. Boat has started and worked flawlessly all season. Got to it today to move it to winter storage and it will not start.

Battery monitor says house bank has low voltage so I replaced start bat anyway as still under full replacement warranty.

Boat has a factory installed engine room blower that runs at full speed when the key is turned, but not even a click from the engine. Had to replace the stop solenoid a couple of years ago, but even then it would crank but not start. Now nothing. No cranking, no click just utter and complete silence except the blower.

Anyone have any thoughts or suggestions? Mooring field closes this weekend so need to fix this ASAP.

Sent from my phone so please forgive any typos.

As always thanks.

Tom

[steffan]

My 3GM30F often does that when it's cold - no click. Short term solution in my case is to keep trying the button. Eventually, it works, might take 5 pushes.

Long term I am adding a relay at the starter. The problem is very likely voltage drop between the switch and starter solenoid.

[Vasco]

Had this engine (4JH3e) for 16 years. Clean all the contacts especially the slave solenoid (bottom right side facing aft). Sometimes this solenoid needs a tap or two with a hammer.

Originally Posted by Tom_F

2004 Jeanneau 40.3 with Yanmar 4JH3E will not start. Start and house banks are isolated, house bank is18 month old AGMs start bat replaced 20 minutes ago. Had the ignition switch replaced in July by certified Yanmar mechanic. Boat has started and worked flawlessly all season. Got to it today to move it to winter storage and it will not start.

Battery monitor says house bank has low voltage so I replaced start bat anyway as still under full replacement warranty.

Boat has a factory installed engine room blower that runs at full speed when the key is turned, but not even a click from the engine. Had to replace the stop solenoid a couple of years ago, but even then it would crank but not start. Now nothing. No cranking, no click just utter and complete silence except the blower.

Anyone have any thoughts or suggestions? Mooring field closes this weekend so need to fix this ASAP.

Sent from my phone so please forgive any typos.

As always thanks.

Tom

[Vasco]

Had one of these (3GM30f) too. Put in a relay from NAPA. There's a diagram somewhere on this site. The 4JH3e already has a slave solenoid. No need for a relay.

Originally Posted by steffan

My 3GM30F often does that when it's cold - no click. Short term solution in my case is to keep trying the button. Eventually, it works, might take 5 pushes.

Long term I am adding a relay at the starter. The problem is very likely voltage drop between the switch and starter solenoid.

[TheOffice]

You have a corroded connection or two. Clean all the cable ends on the starter.
Worst case, jump the solenoid with a screwdriver.

[olaf hart]

Seriously, try tapping the solenoid ..

[Tom_F]

Thanks all. I’ll try tapping the solenoid. If that doesn’t work I’m afraid she is getting towed by BoatUS.

[Lost Horizons]

What is the voltage at the starting battery?

[dougweibel]

I don't recall well the 4JH3E starter setup but I believe if necessary you can bypass the start solenoid using a heavy gauge jumper cable (or a screw driver if you are brave). I'd save this as a last resort.

Another possibility is that your ignition switch has gone bad or you had an open develop in your wiring. In that case you can use a remote start switch in the usual manner.

[boatbod]

Yanmar 4JH3 typically have their harness connectors located right underneath the exhaust elbow. Any leaks causes the rear engine mount to corrode and the harness connectors to become intermittent. Check there first. After that look for a small square solenoid attached to the engine wiring harness somewhere relatively close to the starter motor.

[nwn]

I had the same problem with the same type of engine. My problem was fixed by finding the two relays before the starter and cleaning the spades of the positive wires from the ignition. There is a relay before the starter relay and that was on my engine on the lower part of the engine to he right and relatively close to the starter. I had to take off the alternator to reach it. All connections before the starter relay are low current (Amps) and therefore prone to corrosion.

[Lancerbye]

I hate to post this but i have seen this on several occasions. Are you sure that the shifter is in neutral. I have seen people forget to depress the disengage button on the shifter, move the shifter forward to give the engine a little extra fuel in start up and wonder why the starter does not engage. Just asking.

[Library70]

Good point Lancerbye. Also try holding the key in the start position while wiggling the shifter handle

[Cadence]

If you have a pair of jumper cables, in your car, jump the neg . to the engine and pos. to starter large solenoid terminal. Try your starter switch/button. If that don't work jump the large solenoid terminal to the small one with a screw driver. Your on a short leash time wise, hunt down your bad connections later.

[Redline452]

While cleaning those plugs and connectors, check also the ones behind the engine panel (some of mine have three plugs in series), and if it's a long run from engine to helm/panel, look for an extension. Again, mine has such an extension (with its own set of assorted connectors) under one of the aft berths. There are nearly a dozen connectors involved, and as many series connections from battery to switch to starter.