EE WAS PREPARING TO REPAIR A/C ON A DUMP TRUCK. HE STARTED THE ENGINE, PULLED INTO SHOP AND GOT OUT. HE OPENED THE HOOD AND THEN STEPPED TO THE NIGHT SIDE AND NOTICED A WIRE UNPLUGGED FROM COM PRESSOR. THE WIRE WAS TOO SHORT TO PLUG BACK. HETRIED TO PULL SLACK INTO WIRE AND DOING SO MOVED HIS LEFT HAND, WHICH CAME IN CONTACT WITH ALTERNATOR CAUSING INJURY TO LEFT MIDDLE FINGER.