11 volts at ignition switch sometimes,

[wettrthebetter]

I think this is a ground problem under the dash.
I have a 1991 American Skier, New battery with 12.5 volts  steady, Volts at the starter and Solenoid 12.5 volts steady, Key on not cranking.
Alt 13+ volts when engine is running
Volt meter and ignition switch 12.5 volts some times and sometimes it is 11 volts.
This is the weird thing, I can start the boat no problems, but when I turn off the engine and then turn key on, the Volt meter and my own volt meter show 11 volts, and the engine will start no problem, except ignition switch and dash volt meter and my meter is 11v.
If i Start the engine again and turn it off the Volt meter and the ignition switch goes back to 12.5 v.
This is very strange.
Any ideas?

[wettrthebetter]

Well, No change, I checked all connections under dash, Grounds, and hot.
All hot wires and connections 12.70-1260 Volts.
Replaced the ignition switch, no change.
Engine starts up great, when engine is turned off and key is turned to on position it goes from 12.70 Volts to 11 volts at the ignition switch
the engine starts up great again when engine is turned off again, and then turn key to on position the the volts go back to 12.70 Volts at the ignition Switch.

Oh well I guess as long as the engine starts up with no problems , it shouldn't ruin a ski day.
But the Volts going  up and down Does not make any Sense.

[wettrthebetter]

Update  on volts.
To Hume it may concern or care, The volts stabilized today.
I told her out to the lake today and  the volts at the switch is at 12.70-12.60, charging 13.50.
 So i guess it was the ign switch and Starter Solenoid, cause that is what I replaced.
Thanks for all your replies.