1994 Holden Commodore the car does not want to change gear

my car doesnt want to change its gear.... the alternator is damage .. each time when I repair the alternator, it will run normaly and the gears will work properly, but only for a few kilometers, suddenly the gear doesnt want to change again...when I turn off the car, and I start the engine again , the indicator engine light will not turn off. and the alternator is broken again .