2000 Nissan Sentra - charging problem

2000 Sentra - boils new battery - puts out over 17 volts. Alternator or Voltage Regulator (or one unit?) Thanks!

The alternator has an internal voltage regulator. So the alternator requires replacement.

Tester

Thank you. We’re checking it out now. I’ll keep in touch.

Unless the battery is real new it may be wise to replace that along with the alternator. This should keep you going for a long time without trouble.