Re: What is wrong?
The alternator is probably a CS21. The 12's and 21's are internally regulated, however, There have been many that disfunction and charge at 16 volts or more. Check the voltage at the battery from idle to 3000rpm. If the voltage exceeds 14.8 volts, have the alternator service.
"Acoustics is the study of sound; a branch of physics dealing with sound. The law of physics is constantly challenge. Therefore in relation to acoustics; You must study constantly, for you will be constantly challenged." ...... Rainmanspl