Have I killed my alternator

[davidwf]

Somehow the on off switch got switched off on my Yanmar the other day. Discovered it when I tried to switch off engine and solenoid failed to operate. Noticed that voltage from alternator is now about 13.8 V I'm sure it used to be over 14V.

Do you think I've damaged the alternator, battery was not disconnected only key switch was off.

 

[sailorman]

"Key Switch"
is that the engine key or a 1,2,Both switch ??
if you are still getting 13.8v i guess its ok.
as long as the alternator was still connected to the 12v in some way cant see a problem

 

[davidwf]

It was the engine key.

 

[sailorman]

i think you are ok.
the voltage will depend on how far charged / discharged

 

[ccscott49]

If its putting out 13.8, its fine.

 

[William_H]

Just to really make sure the alternator is OK run the engine with every DC load you can manage turned on so that the alternator should be producing 20 amps or so. If it will maintain 13.8 volts for a period ie 30 mins then the alternator is fine.

They can have a diode failure which will produce normal voltage but not be able to manage the voltage under load. It is probably however. olewill

 

[SwedishLass]

Did same at the beginning of the season by catching keyfloat which turned key off. I did blow alternator but the symptoms were 16+ volts as it screwed the regulator. £60 later at a local auto sparks... 13.8V should be ok
I think max is normally 14.2 dependent on reg but obviously doing its job. Similar symptoms on previous boat (but not my fault that time!)

 

[pampas]

Once running, switching off the ignition switch is no worse than the warning light bulb failing in sevice, the only difference being that other equipment might cause problems ( if fresh water cooled the pump might stop), and you would have no alarms systems operative ,so please try not to make this a habit.

 

[Heckler]

On the VP MD22 diesel engines you switch the ign off and go past that position to operate the solenoid to stop the engine, so you should be ok
Stu

 

[StugeronSteve]

We accidently switched the ignition off on our Volvo, with no harm done. I think it is isolating the batteries that causes a problem, with nowhere for the charge to go it fries the diodes. My simple check was to load the system up with everything lights, nav, eber and Uncle Tom Cobbly and all, then check the voltage with the engine off and on.

 

[sailorman]

we have i or 2 permanant feeds - Radio,bilge pump.
these have saved the day more than once