Shaft alternator on Santorin don’t work


Dear Amelians, I hope some of you can help me solving my problem. My 1994 Santorin is, as usual, equipped with a shaft alternator. Last year I made a check of the alternator because it didn’t work correctly. The check was ok : the alternator worked normally “ at the bank”. I put it in place again. But now, when I turn the key in the galley in order to activate it, only the red lamp light on but the propeller continues to turn free and the green lamp doesn’t light up.
I checked the wiring coming from the key to the alternator and something strange came out: when I turn the key ON, no volts are checked; if I turn the key OFF, the tester tell me 13V. May be some of you could suggest me how can I control the wiring better ? Or something else? 

I really hope you can understand my poor English. Thanks everybody for the attention. Fair wind
Santorin #93
Actually in Corse

Join to automatically receive all group messages.