Ignition switch

Sep 8, 2009
19
Hunter 335 Lake Guntersville
I have a 1989 Hunter 335 with a 2GM Yanmar. Should I leave the ignition key in after the motor starts, or take it out?

I think I worded the question badly. What I'm trying to decide is what type of toggle switch I should get to replace the key switch. Should it be a normal on/off switch, or one that is spring loaded and always returns to the "off" position when released?
 
Last edited:
Feb 21, 2013
4,638
Hunter 46 Point Richmond, CA
I always keep the key in the ignition switch...............because if you need to quickly turn the engine on you do not have to go looking for the key and its always in the same location.
 
Feb 26, 2004
22,752
Catalina 34 224 Maple Bay, BC, Canada
Don't you have to investigate (or know) what else, if anything, that switch energizes? Perhaps not on your boats but on mine, it keeps the regulator on the alternator energized and works the tach. You may have a mechanical tach, in which case it won't.
When we shut down our engine, we remove the key when sailing, but hang it closeby on the engine kill switch for immediate use.
If it can be knocked and broken in its position, leaving the broken part inside the switch, of course, take it out. If it's not in the way, why ask? :)
Good luck.
 
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Likes: ggrizzard
Sep 25, 2008
7,068
Alden 50 Sarasota, Florida
I always keep the key in the ignition switch...............because if you need to quickly turn the engine on you do not have to go looking for the key and its always in the same location.
Good point. Anticipation is the ‘Key’ to good seamanship.
 
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Likes: LloydB
Oct 28, 2018
45
Hunter 31 Duncan Bay
Turning the key off while running will ruin the alternator according to Yanmar, so it must be a standard switch not spring loaded
 
Feb 26, 2004
22,752
Catalina 34 224 Maple Bay, BC, Canada
Turning the key off while running will ruin the alternator according to Yanmar, so it must be a standard switch not spring loaded
I find that hard to believe. All an ignition switch can do is energize the regulator, internal or external. Interrupting the AO is what kills alternators.
Could you explain please?
 
Jan 4, 2006
6,439
Hunter 310 West Vancouver, B.C.
Turning the key off while running will ruin the alternator according to Yanmar,
Could you please supply a copy of these Yanmar instructions ?

I'm intrigued as to how a boat could be wired as to disconnect the alternator from the battey(s) when the "so called" ignition key is turned OFF.
 
Oct 28, 2018
45
Hunter 31 Duncan Bay
all I have is the instructions that stated turning the switch of would result in dammage. my manuals are at the boat so give it a try.
 
Jan 4, 2006
6,439
Hunter 310 West Vancouver, B.C.
I don’t know why.
BECAUSE ...................... remember you heard it here first. Are you ready for it ? Drum roll please :dancing: !

"If you shut the switch OFF first, you will not have any engine alarms"

And it also checks out your oil pressure switch.




 
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Likes: ggrizzard
Jan 4, 2006
6,439
Hunter 310 West Vancouver, B.C.
This statement probably applies to the battery selector switch not the ignition switch.
I wish to nominate @Ted for the first prize of a kepie doll.
1619741043622.png

And it's gender neutral for all you politically correct (PC) types.
 
Feb 26, 2004
22,752
Catalina 34 224 Maple Bay, BC, Canada
Is there an emoji for SWITCH CHALLENGED?

I have light switches, a battery switch, and an ignition switch.

I tried real hard when I bought the boat to learn the differences.

Then I went and read the paper manuals.

Then I made sure I had every single manual available in electronic form, so I couldn't claim I didn't know because "it's on the boat."

Maybe it was the light switch...
;)

i do covet the kewpie doll though...:stupid:
 
Oct 28, 2018
45
Hunter 31 Duncan Bay

So I am not taking chances.
On the other hand, you have also disconnected all warning lights and buzzer. So if you lose oil pressure no warning sound, just a blown engine.
 
Oct 28, 2018
45
Hunter 31 Duncan Bay
More than just a rumour.

The problem occurs because of output current is interrupted thus its EM field collapses cutting the stator coils of the alternator. This sudden collapse of the field through the coils creates the voltage spike that kills the diodes.

The size of the spike is directly proportional to the size of the output current at the time it is interrupted i.e. large current, large spike and vice versa.

Modern alternators have the same coils and the same diode packs so the problem remains the same.

Note, the regulator itself is not affected.
 
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Jan 4, 2006
6,439
Hunter 310 West Vancouver, B.C.
And you're telling me all this occurs because the key has been turned OFF ?

Enquiring minds want to know.
 
May 24, 2004
7,129
CC 30 South Florida
I think Yanmar instructions refer to the battery switch. I keep my key switch On all the time as it powers the Hour Meter. Have on occasions accidently turned it Off with no adverse effects to the alternator.
 
Oct 29, 2005
2,355
Hunter Marine 326 303 Singapore
Somewhere in there it says turning the key switch off while engine still running will kill the alternator diodes. If you wish to change the key switch to an On/Off toggle switch, suggest you get the Locking Lever type to prevent accidental switching off when bump into.

Ken Y