How Do You Wire a Yanmar Start Solenoid ?

[capbillh]

Hellosailor, the starter current, in my case is 1.4kW so at 10v = 140 amps goes thru the starter solenoid, not the "starter key" switch. The current is only to activate or draw in the bar against the spring in the solenoid casing.
Looking at my 2006 Acura starter circuit in the shop manual the solenoid activation current DOES run thru the ignition switch besides relay current going thru a neutral safety switch/clutch interlock in the trans.

switch------coil----trans switch---grnd
................I___------solenoid

Above is a rough schematic from the Acura Shop manual
Also, when the switch is in "start" position notice that the alarms are turns off as in a car thus stopping any unnecessary current to keep the voltage up just for the start mode.

Capt bill K2SDV

[hellosailor]

Bill-
"140 amps goes thru the starter solenoid,"
That IS what I said. A starter solenoid relay can be internal in the starter housing, or external in the harness or mounted on the starter. That's all the same thing, in terms of whether someone is or isn't going to use a "relay" as opposed to just a starter button. As long as that button is throwing a relay, somewhere, the electrons are happy.

[capbillh]

No, that is NOT what you said. You stated that one needs to look at the rating of the key switch vs the current that the starter draws. You indicated that the starter current was going thru the "ignition/starter" switch thus a relay would be need. That NEVER happens in any system. The "relay" that is always there is the starter solenoid. In a boat system an additional relay is not really necessary as in an automobile arrangement.
The starter solenoid is always necessary in any engine in order to engage the starter gear with the ring gear of the fly wheel.

[hellosailor]

Bill?
Context is everything. What I said, was a reply in the context of "You don't need a relay" and my answer was to that context. If you don't have a relay SOMEPLACE then you need to look at the rating on the starter switch versus the load on the starter.
I think we've both misspoke here, when you say "140 amps goes thru the starter solenoid" I really doubt that. The solenoid--the throwout aka Bendix--does NOT carry the full load of the starter motor. That 140 Amps is being supplied to the motor's windings, and only a fraction (a couple of amps) goes to move the solenoid itself. The solenoid only bumps the starter motor against the flywheel so they are connected during starting. The bulk of the current goes only to the starter motor windings--not the solenoid.
And in order to apply that current to the starter motor, a RELAY is used. The relay normally applies power to both the motor and the solenoid at the same time. The original question was whether a failure-prone additional part (the relay) was needed or not.
The answer to this was and still is, a relay is necessary OR ELSE the starter button has be rated to supply the full current load to the starter, motor windings and solenoid together.

AFAIK, there is always one relay supplying power to both the solenoid and motor windings, whether it is called the starter solenoid relay or starter relay depends on which maker is doing the calling.

[SeaKing]

Originally Posted by Chief Engineer

To eliminate the starter button problems?

Now that is funny, a Chief Engineer asking how to wire a SIMPLE DC circuit.

[Chief Engineer]

Not really, there has been much discussion in many circles about the various ways to circumvent this somewhat common Yanmar Problem.

All I asked for was others input.....how they solved the problem.

[SeaKing]

Any QUAILFIED Chief Engineer would not have to ask that question and should be embarrassed to let potential clients know his limitations on basic fundamental DC circuits.

[Chief Engineer]

This is a discussion...seems like it was about 50-50 separate solenoid vs larger wire.

I could have gone either way.....but since the customer is happy with the result....I'm happy........

[IdoraKeeper]

I would like to clear up the intent of my contribution. I agree that the relay whould be there for "normal" starting. As these things get older they tend to accumulate wear and become cranky on occasion. You may even get dead spots in the starter motor. The "momentary Switch" is for occasional nonnormal use hence the idea of putting it in an accessable but out of the way spot. Every time I have used mine I find that the relay controlled system regains function and works for a long time after. I think the momentary switch will last a long time if rarely used.

Todd

[capbillh]

Hellosailor, you still do not get it. The solenoid IS the relay to route the current to the motor AND engage the gears at the same time.
Unless you have experience with some very one off equipment, most all cars, trucks etc have the dual function starter solenoid and have an additional relay for other purposes as I explained for my car. The 2nd relay is not REQUIRED in a simple setup as in a boat. The matching of the rating of the solenoid with respect to the starter current was done by the manufacturere of the motor as a package.
I eliminated the corrosive prone connectors which even if a relay is used the resistance would just continue to increase.