Turning Key 'Off' While Engine is Running

[sandycohen]

Hi All

Since I bought my boat a few months ago, which has a yanmar 2gm20f inboard diesel, I've gotten in the habit of taking the keys out of the ignition after the engine is running, so they can't get knocked around or bent in the lock. The engine does nothing I can tell adverse when I turn the key 'off' and take it out.

Last night i was looking at the manual and it said something about not turning the battery switch or ignition switch off while the engine is running as it can hurt the alternator or starter motor. It put these two things in the same sentence, but I am only turning the ignition switch off, not the battery. Is this harmful, or does it stop the alternator from charging (either one is problematic).

The keys are so vulnerable just hanging in the panel I hate to leave them sitting there the whole time we motor...

Thanks!

[Mardav]

Depends on how the ignition is wired. If the switch is in the charging circuit you will damage the alternator (you could for example blow a diode, which would either prevent the alternator from charging or allow the batteries to feed back to the alternator when the engine is off). If the key is out of the circuit and only provides exciter current when starting, nothing will be damaged.
Why don't you just use a separate single key that is unobtrusive and eliminate the guess work?

[Vyndance]

Yes you are probably turning off the alternator by killing the sense wire unless it is a single wire unit. No problems with the starter. You are turning off your alarms.

[senormechanico]

If there could be any damage by removing your key, it would have already happened.
Just make sure if removal of the key shuts off charging that you don't run the battery flat.

[sandycohen]

Vyndance - Thanks - the alarms is enough reason NOT to turn if off for me, that's something I should've thought of, but that's why forums are good!

I was going to ask Mardav how I tell how it's wired, but it doesn't matter - I don't want to lose my alarms while running!

I will use a single key, but it's still something to stick out in the cockpit, and remember to remove before we start racing, and then if need to start the engine in a hurry have to find and replace in ignition.

Thanks Guys!!

[John A]

I'd think that the manual supplied by the manufacture should take precedece over all other considerations.

[SaucySailoress]

How far out does your key stick? Most keys I have seen are just little things, that don't really cause a problem by being in situ.

[SkiprJohn]

If the key switch is vulnerable where it is I'd consider changing it's location.

kind regards,

[DotDun]

Take a spare key (it case it breaks) and bend it so it's out of the way.

[Mark Johnson]

Originally Posted by sandycohen

Hi All

Since I bought my boat a few months ago, which has a yanmar 2gm20f inboard diesel, I've gotten in the habit of taking the keys out of the ignition after the engine is running, so they can't get knocked around or bent in the lock. The engine does nothing I can tell adverse when I turn the key 'off' and take it out.

Last night i was looking at the manual and it said something about not turning the battery switch or ignition switch off while the engine is running as it can hurt the alternator or starter motor. It put these two things in the same sentence, but I am only turning the ignition switch off, not the battery. Is this harmful, or does it stop the alternator from charging (either one is problematic).

The keys are so vulnerable just hanging in the panel I hate to leave them sitting there the whole time we motor...

Thanks!

I would NOT remove the key with the engine running, as the manufacturer says...

The solution, is to recess the panel. It will last indefinably if you do so. They do not do so well left out in the elements.

There is a simple fix... (I have the same engine panel BTW). Just get a Beckson, "vertical" mount, exterior hatch & frame. They are not as rugged or watertight as the dogged ports, and are not meant to be. They have a 1/8" thick clear lid, hinged at the top, and a handle at the bottom that snaps closed. These come with a 2" spigot, and the size you need is the one that's about 8" tall, and 14" long.

You scribe the spigot onto the papered face of a piece of white, opaque PlexiGlass, and cut it out. Then, in the middle of the round cornered rectangle that you just cut out, cut a square hole for the panel, and temporarily mount it. (Then remove it.) You can tap threads into the PlexiGlass, gently, and use SS machine screws, for mounting the panel.

Now you solvent weld this piece of PlexiGlass onto the back of the hatches 2" spigot, using Methylene Chloride, and a syringe with flat tipped metal needle. (There is a kit available for this, at the places that sell PlexiGlass).

Now you have a clear front lid, vertical mount hatch, with a back wall that is recessed 2" back from the face flange. Your engine panel will mount into the hole you previously cut in the back wall.

Now mount the hatch in the footwell, or where ever, and then mount the engine panel into the hatches recessed back wall.

If memory serves... You are talking < $50 in materials, TOTAL, an hour to make the hatch recess, and perhaps two hours to make a cut out, and mount the hatch & panel. This a small price to pay to have the panel recessed & out of the rain and spray, out of the "kick zone", conveniently located, that you can easily hear, and covered with a clear lens, so you can see it too.

My 15 year old panel is in one of these recessed hatches, and looks, as well as works, like a new one.

Mark