Engine turned over by a/b switch only ???

[Joe23455]

Need some insight. Yanmar 2qm20f 1980, runs great. On the hard over the winter, no issues with A/B switch turning on lights, etc.
Yesterday, I went over Engine connections, hoses, etc. Launching in two days.
Today turned A/B switch to check some accessories and the Starter Engages ! Perplexed. Disconnected the starter push button to
take it out of the picture incase that was malfunctioned. Turned the A/B battery switch and the Starter Engages.
Could it be the selonoid is shot ? Appreciate some help.

s/v Trinity

Joe

 

[Ralph Johnstone]

Invest in a cheap multimeter rather than all of us sitting around, throwing guesses up into the air, to see what sticks.

See if the starter solenoid is closed when the batteries are disconnected using the A, B, AB, OFF switch. The starter should grind itself into a fine powder if that's the case.

No multimeter - no idea.

 

[Michael Davis]

Invest in a cheap multimeter

May as well get a decent one. You have a boat so you will get lots of use out of it. Very handy around the house too.

 

[heritage]

Once you have a multimeter in your hand, I would suggest doing a continuity check between the two large lugs on the front of the starter solenoid. Do this with the ab switch OFF. If continuity is present, tap the top of the
solenoid with a wrench and try the continuity test again. If there is no longer continuity, it means that the plunger inside the solenoid was stuck in the closed position. Time to buy a new solenoid.

 

[Joe23455]

Thank you all for your input, took solenoid off starter, removed plunger and torsion spring, cleaned, lubricated re-installed. All works well. Launch tomorrow.

 

[kappykaplan]

All works well.

Great outcome! Now you don't have to figure out how to put smoke back in the starter.