If your charging at 14+ volts, I'd be looking at an alternator problem mate. There's a regulator on the back of alternators to cut in at a preset low voltage and then cut out again at a preset high voltage, which is not over 14v. It regulates at all times and allows the alternator to run "off load". Sounds to me like its over charging.
it can be set as high as 14.8 volts, but is, typically, 13.8-14.2 volts.
Alternator voltage test. Connect the test leads of a volt meter to the alternator output terminals. Note:
Most Leece Neville alternators have isolated ground rectification. Always connect tester / volt meter
directly to the negative output terminal of alternator or your test will be inaccurate.
• Start engine, increase to high idle (1500 RPM): The volt meter should now indicate that the alternator
output voltage has increased to a range from 13.8 volts to 14.2 volts. (Ensure that all electrical accessories
of the vehicle are in the off position.) If voltage increases but is out of range, inspect to see if alternator has
an adjustable regulator. If so, reduce engine speed to idle and adjust voltage to a setting of 14.0 volts. If
voltage is higher than 14.7 volts and cannot be adjusted below 14.25 volts, or if voltage is lower than 13.8
volts and cannot be adjusted into range then replace alternator.
• Inspect if voltage does not increase: If the alternator incorporates an ignition (IGN) terminal this
terminal must have battery voltage present above 12.4 volts. If not; inspect circuit for open and
repair. If all is verified and alternator voltage has not increased or is out of range replace alternator. If within
range go to Step 5 (enter voltage into box 3 on page 2).
