Why is my charging system goes over 15 volts when I raise rpm
4 Answers
check your voltage regulator..and/or maybe alternator..some voltage regulators are internal (inside alternator)..
How high does the voltage go? 14.0 to 14.6 is normal, but anything much higher than that may indicate a bad alternator or voltage regulator (likely built in to the alternator). Very high charge voltage is hard on light bulbs, batteries and other electronic items. I would use a volt meter to measure the voltage, engine running, at the battery. If out of spec. get the alternator tested.
Most likely bad voltage regulator like mentioned. It can also overcharge battery, cause warning light to come on or give bad reading on gauges.