yanmar start switch hangs -voltage drop

[jtm]

I have replace the key cylinder and the start button..... but still have this nagging intermittant "hang"( whistle sounds loud and clear {so batteries are fine} but nothing more) from the start button. This can happen at the worse of times. It may take several attempts before it starts as it should - but the uncertainty is unacceptable. It seems to happen on the 2GMF and 20 as well as some 3 cyl models. My readings on Torresen's site appear that its the loss/drop of several volts in the start button circuit. Folks have indicated that they have created a back circuit of the start button and installed a Cole Hersee (4 lug- low and high amp sides)solenoid to eliminate the lagging voltage issue. All mentioned this solved the disconcerting problem. Is there a circuit diagram available from Hunter/Yanmar or from any one detailing this "fix". I am very tired of playing "starter roulette" with the original setup. I'd appreciate any input on this topic.

 

[uptownsteve]

Intermittant starting problem

I have a similar problem with my 3 cylinder Yanmar on my Huner 386. I get the alarm "whistle" but no ignition. I have cleaned all connections to the key switch, push button starter switch and to the starter solenoid. In my case the engine always starts instantly when cold. The problem only occurs when the engine is shut down and then restarted shortly thereafter.The last 3 times this happened I was able to start the engine by fidiling with the key switch, the starter button and yesterday by taking the shift lever in and out of neutral. I though perhaps there is a device for preventing the engine from starting in gear and that perhaps in needs to be realigned.The next time it fails I will try jumpering across the terminals of the key switch, and push button switch to eliminate resistance within the switches.My switch panel is made by Seaward. It is not a Yanmar panel. There is no schematic of the switch wiring to this panel in the Hunter supplied manual.Based on your comments it could well be a solenoid problem. One way to determine if it is a solenoid problem would be to temporarily jumper across the low amp terminals of the existing solenoid. This would bypass the key switch, the starter button switch and any voltage drop in the wiring of these switches. If the engine starts then the solenoid is at fault.I do not understand what you mean by creating a "back circuit" or why you would need a 2nd solenoid.Steve

 

[Neil McDonald]

Yanmar Start Problems

This topic has been covered several times before and can be found in the archives. Everyone seems to agree with your conclusion that too many connections in the starter button wiring circuit cause an excessive voltage drop and as a result the installed starter solenoid does not receive sufficient voltage to actuate. My own theory as to why the starter frequently works after a few tries - developed at the helm on a recent Gulf of Georgia crossing - is that high resistance in this circuit creates heat, which lowers the resistance, which increases the voltage and... bingo the problem goes away until the next time. The solution involves a very small investment in a 12 volt relay - under $10 -the one that I bought was rated for 30 amps but this is probably overkill. If this purchase did not include a relay wiring diagram, play around with it (off the boat) until you discover where applying 12 volts from any battery across two of the relay terminals (the control voltage) will close the circuit across two of the other remaining terminals. Note that this correct relay response is sensitive to the direction of the applied voltage, ie polarity counts! As a clue, the new relay may have noticably less substantial tags on the side of the relay that the control voltage should be applied. Make careful notes on what you have just found! Disconnecting the batteries before you start work, locate the Yanmar supplied solenoid on the side of the starter motor and find the wire that feeds it with the control voltage from the starter button. Cut this wire near the solenoid and then connect the wire from starter button to the control voltage side of the new relay. The other side of the control circuit on the new relay should be wired to any convenient ground. Make sure that you have the correct polarity. You have just created a circuit that will reliably activate the new relay when the starter button is punched, one that is not very sensitive to the reduced starter button voltage that created your problem in the first place.Then find a new source of unswitched electrical power in this vicinity, possibly on the starter motor, and wire it to one of the other terminals located on the opposite side (the power side) of the new relay. It does not matter which of the two power terminals on the new relay that you use. Lastly connect the remaining end of the original wire leading to the solenoid, the one that was cut in the first step above, and connect it to the remaining terminal on the power side of the new relay.It is actually simpler than it sounds! Good luck.

 

[jtm]

clarification

I should have said a solenoid "relay" - sorry for that oversight.I haven't located a skematic for this solution. Thanks for the comments. Still seems that this original design problem should have some remedy made available by yanmar and/or Hunter.

 

[Chuck]

Relay diagram

This should be a link to relay diagram.

 

[GuyT]

Sad truth

is that you probably did not need to replace any parts.This problem has been posted many, many times. It is a common problem.There are just too many connectors to get corroded between the solenoid and the control panel.A solid wire run from the solenoid to the panel could be a solution. Just take a wire and run it next to the cable harness and bypass or parallel the existing solenoid wire.The relay solution would also work and may be a better solution because of less voltage drop but, the solid wire connection will get you back to original condition.

 

[jtm]

thanks for all the detailed help.

thanks for the diagram.I saw an 85Amp cole hersee relay @West Marine for about $46.Thought 85 Amp was overkill.... and Neil thinks 30amps was overkill.I like his $10 price better but 30A not carried @WM.2nd question-Folks have also inserted a 2nd starter button in the engine box and they mention to be sure to insert a fuse for it - what size?? thanks

 

[Patrick]

Change the solenoid

Had the same problem on my 3gm30, then one day I had the engine cover off and heard the click when it wouldnt start. I spent $100 and bought a new solenoid, it hasnt happened since. Take the starter off the engine when you change it, much easier to get the little magnet thing lined up.

 

[Benny]

Don't overlook the wiring harness.

I traced a similar problem to the wire harness between the control panel and the engine. The harness was chaffing when going around a sharp fiberglass bend and it had worn the insulation off and was starting to cut into the (+) wire. It had cut through about 25% of the strands and was ging me a voltage drop. The activation of the starter solenoid had become erratic. Sometimes it would take three or four times to push the button before it engaged. The wire was cut and spliced and insulation was added with electrical tape and the problem went away.

 

[Neil McDonald]

For JTM

Nothing against WM but I avoid all marine chandlers if I can get suitable stuff elsewhere. Saves big $'s that way. Several people have found suitable relays at Radio Shack, my local RS branch did not stock them - but did tell me where to find another local electronics store that did. Just to make you weep, this store had a selection of relays costing between $3.00 and $6.00 and that was Canadian $'s!!! Since this new relay is controlling the power supply to a solenoid (solenoid is really just another name for a relay) it does not need to have much power handling capacity. While purists might argue with me, fuses on most things except electronic gear on a boat are mainly intended to prevent possible fire risk in the case of a total short, so any medium rated fuse will likely do the job.