First, fix broken wires
Second, look at an engine wiring diagram and make sure it's hooked up correctly.
If it was hooked up correctly just replace the alternator as well as voltage regulator to error on the side of caution. Both are inexpensive. Make sure your voltage regulator has a good ground. I run a ground wire from battery negative to my voltage regulator mount. If your mounting bolts on the voltage regulator are a little stripped just put a small screw directly into the voltage regulator mounting flange to achieve a good ground.
