Motor won't turn over, starter?

[Dougcole]

Mainship 400, Yanmar 4LHA-STP. Micro Commander controls. Starting sequence is: 1. Turn on engine breakers. 2. turn off/on/start switch at helm to on. 3. Call for throttles at control box. 4. Push switch to start.



The last few times I've run the boat, on my stb engine, every fourth or fifth start, when I press the start button I've gotten nothing. Push it again and the negine starts right up, no dragging or anything. Today, I went through my sequence and I'm getting nothing. The low oil pressure alarm sounds (as usual) and the control box light comes on, but engine doesn't even click. Paralleled the batteries, nothing. The port engine, which is on the same starting bank fires right up.


I've got 12.7 volts at the main cable coming from the battery to the starter. And 12.7 on the solenoid post.



Tried both the lowe and upper helms thinking it may be the switch and neither works.




I'm not sure how to check for voltage drop because I'm alone at the boat and can't push the switch and hold my meter on the solenoid at the same time.


Suggestions?


TIA.

 

[Pau Hana]

Can you swap the start switches (port to starboard and vice versa) to confirm/eliminate the switch?

 

[High Wire]

No click at all?
Hold the start switch to start position then wiggle the shift lever. Could be the neutral safety switch.

 

[Comodave]

Or just jump the terminals on the start switch to activate it.

 

[Dougcole]

Or just jump the terminals on the start switch to activate it.

I don't think it is the switch at the helm, because it's not starting at the upper helm either.


The Neutral safety switch is a little different with electronic controls, if the throttle is not in neutral the control box won't activate. The control boxes at both the lower and upper helms are lighting up.



When I hold the start switch down and put the shifter in gear, I'm hearing a little grinding noise from what I think is the starter. Tough to say without being in the ER. I really need a second person.

 

[foggysail]

I saw a similar situation with a Crusader 454. Problem was a failed riser allowing water to gain entrance into the cylinders. Be careful, if the same it might cost you a new engine. The described engine could have been saved if we had pulled the plugs and then done the cranking. We did get the thing to eventually crank and start on about 3-4 cylinders. Engine was then junk

 

[Dougcole]

I saw a similar situation with a Crusader 454. Problem was a failed riser allowing water to gain entrance into the cylinders. Be careful, if the same it might cost you a new engine. The described engine could have been saved if we had pulled the plugs and then done the cranking. We did get the thing to eventually crank and start on about 3-4 cylinders. Engine was then junk

Thank you, but my exhaust elbows and riser are in great shape, I replaced them about two years ago and then pulled the hose off and checked them about six months back. The enigine runs perfectly once it starts, and starts right up as soon as it gets power. I just ran it three weeks ago.


It's some sort of electrical issue, may have something to do with the electronic control actuator.

 

[foggysail]

That is great news. Electrical should not cause engine damage

 

[Dougcole]

Did some closer listening. It's not the starter grinding when I hold the switch down and put it in gear, it's the electronic control's actuator. It is the sound of it shifting the engine into/out of gear.


Seems as if it working fine.


Solenoid or a connection at the solenoid?

 

[Boat]

Could you use a horn like a test light? Maybe you can hear it instead of see it. Or use a length of phone wire for a really long test light.

 

[C lectric]

Engines often have a pilot or intermediate relay between the actual starter mounted solenoid and the key switch. Those relays can cause the trouble you describe. Over time their contacts burn and the operation becomes intermittent so the starter solenoid does not get power. Your ignition key switch often cannot handle the current of the starter solenoid so the pilot relay is needed.

Take a look for that relay which is usually close by to the starter motor.

I will add that the starter mounted solenoid can also cause that trouble since it too has contacts that close at the last bit of the pinion drive motion.
The pilot relay is more likely the unit to cause trouble.

 

[Dougcole]

Engines often have a pilot or intermediate relay between the actual starter mounted solenoid and the key switch. Those relays can cause the trouble you describe. Over time their contacts burn and the operation becomes intermittent so the starter solenoid does not get power. Your ignition key switch often cannot handle the current of the starter solenoid so the pilot relay is needed.

Take a look for that relay which is usually close by to the starter motor.

OK, that makes a lot of sense. Any tips on what it would look like, or how to trace to it? Since it is a relay, should it have fairly substantial wires coming in and smaller coming out going to the key switch?




Thanks.

 

[C lectric]

Yes the pilot relay will have one or two small guage control wires. Sometimes these things are grounder through the mounting on the engine.
The other two wires will be much heavier as they are the ones that feed power to the actual starter solenoid.
The starter solenoid will have a smaller wire leading to it , than the main power for the actual motor,. so follow that wire back to the pilot relay.
Some pilots are a bit smaller than your fist, round basic shape such as made by Cole Hersey.
There are other relay designs used which are more like a tower but with those connections.
I can't tell you which your engine has but be aware that some engines MAY have two/three of these relays, one only for the starter. The other one or two will likely be for electric heaters to aid in smoke reduction after starting but have nothing to do with the starter. Just trace the wiring between the Pilot and the solenoid to be sure.

 

[Dougcole]

Update.


Called the local Yanmar dealer/service center and spoke to the shop manager who told me that yes, there is a "helper relay" on my motors, and that they frequently fail. When I described the symptoms to him he said that a failed relay would be his first guess. I have to be away from the boat for the next ten days, and then we are planning on heading for the Bahamas, so I called the marine electrician who has worked on my boat before. He got down to it this afternoon.


Predictably, when he hit the switch the motor fired right up. He started it 12 times in a row with no failures.


I think I'm going to buy a pair of relays, and just go ahead and replace it. Second one will be a spare or for the other motor.

 

[Baker]

No click at all?
Hold the start switch to start position then wiggle the shift lever. Could be the neutral safety switch.

This is what I would think would be most likely.

 

[markpierce]

No click at all?
Hold the start switch to start position then wiggle the shift lever. Could be the neutral safety switch.

The only times my engine failed to start was when the shift lever wasn't exactly spotted at neutral.

 

[Dougcole]

The only times my engine failed to start was when the shift lever wasn't exactly spotted at neutral.

This is what I would think would be most likely.

I have electronic controls, the neutral safety switch works differently with them than with conventional controls. The control head won't activate unless it is in neutral, and if it is not activated the engine won't start. Both of my control heads are activating.

 

[PM]

Right there is what I DO NOT like about the upper tier diesels. Too much electronic intervention. It is not foolproof!

That being said, I think what you are looking at is a bad starter (or going bad). Next time it happens take a wooden mallet or rubber hammer and give the started a few "raps" if it kicks in next time you try it, you have found your weak point, rebuild it.

pete

 

[sunchaser]

Doug
Celectric gave you a great tip regarding relays. Does your engine have a few spade fuses close by the relays and protecting the start sequencing systems. Your engine manual wiring diagram will show each one's function. Sometimes these fuses need a cleaning to remove oxidation.

Does the transmission have a neutral switch mounted on it, it should. This switch (and others in the start circuitry) will connect up to relays and fuses in the start wiring. Wiring around engine start circuits built during the past 20 years or so, like battery cables, require periodic cleaning.

BTW, how old are your starting batteries?

 

[High Wire]

Those "helper" relays are relatively cheap and easy to replace yourself. Replace one and keep a spare. Last resort is to use a pair of jumper cables (everyone has a pair right?) from battery to starter solenoid or the starter motor itself. Good practice drill for a rainy day.
I am concerned about the controls trying to shift during start attempt. That should not happen.

 

[bayview]

First check all battery connections. It is common to get good voltage readings while bad connections limit high starting current

 

[Baker]

First check all battery connections. It is common to get good voltage readings while bad connections limit high starting current

I was embarrassed by this once. Had a whole group on the boat. Hit the starter and click....nothing. My battery connections LOOKED good. But my neighbor(and good friend) came over with a brush and loosened each connection and brushed and cleaned them up. And then engine started just fine and never gave me trouble again.

 

[sunchaser]

I was embarrassed by this once. Had a whole group on the boat. Hit the starter and click....nothing. My battery connections LOOKED good. But my neighbor(and good friend) came over with a brush and loosened each connection and brushed and cleaned them up. And then engine started just fine and never gave me trouble again.

We may have a winner, third post to mention batteries or cables. Doug?

 

[Dougcole]

We may have a winner, third post to mention batteries or cables. Doug?

Could very well be, I replaced my start battery back in the fall of '19. September or October. I won't be back down to the boat until early next week, I'll clean up the connections. My electrician said the battery connection "looked good," but I agree, it could be an issue. I've had that happen on other boats.



Now that I think about it, he also said my port motor didn't kick off once when he tried it, and both motors start from the same bank. I'm virtually 100% certain the battery is good, and paralleling the house bank with the start bank didn't fix the problem. That says bad connection to me.


On the other hand, my plan is to get a couple of relays, replace the starboard one, keep the other as a spare. Just to be safe.



Starter is very strong once it gets power, I don't think that is the issue. Electrician feels the same. Could be the solenoid though. So frustrating that it didn't do it when he was there.


As far as the trans trying to shift, that only happened because I was putting it in gear with the start switch activated.

 

[Dougcole]

Got down to the boat last night. Started it 6 times this morning before I did anything to it, it fired right up.


Checked the battery connections and the connections on the battery switch, they look great, tight, no corrosion, clean and bright.


Decided to change out the relay anyway, so I bought one from Shearwater, $185, which is really high for a little relay (never change Yanmar), but their service is fantastic. They walked me through what to look for.


I was concerned because I expected the relay to be close to the starter and I couldn't see one there. Turns out it's not close, not close at all. The wiring harness runs from the solenoid around the back of the engine then midway up the stb side where the relay is mounted to a bracket. Of course, this is on my starboard engine, whose starter is on the port side, super easy to reach, so I was not happy that the relay is on the other side of the engine...a bear to reach. Would have taken me 20 minutes on the port side, took an hour or more on the stb.


New relay is in, and the motor starts very quickly. I'm hoping that the issue is now fixed. I bought a remote starter switch to make it easier to jump the solenoid if needed. Not sure what else I can do.


Thanks everyone for the help. Especially C-lectric. It appears your diagnosis was correct.

 

[eclavoie]

My Chris Craft w/Crusader engines had a similar issue on the port side only. 12.7v at the starter solenoid would drop to 3v when key to start position. After replacing both relays and the starter solenoid, I found the 12v fuse supplying the ignition switch was corroded. Cleaned it up and problem was gone.

 

[Easternshore]

Micro commander issue?

Check the plug connectors near the M/C computer box for corrosion and the solenoid, I experienced both issues on my Pilot 34, had the connector corrosion when we purchased the boat, the “big” mainship dealer was clueless, we did find a good marine mechanic who diagnosed the problem. Last year starboard engine would not start, the solenoid failed. The solenoids (pictured) were hidden on a bulkhead above my batteries. I replaced both and no further issues. Both engines start just fine.

 

[bykpjfk]

I have the same engines in my '97 mainship sedan bridge, and I've had to replace one solenoid twice. Yep, $185 is steep. If I was smarter, I could figure out how to use a $9.95 fomoco solenoid.
Dan
Passport

 

[db2]

Check the battery switch to the engine. They go bad, it happened to me and my CAT 3208. Put all the cables on one post and see if the starter cranks.

 

[Easternshore]

I bought My solenoid at West Marine $29.95, starts great.