Alternator died a few years ago and i replaced it with a Bosch alternator. Now im getting intermittent charging. I have a voltmeter(Turbotimer with volt readout) hooked up and while the car starts and runs and drives fine, the alternator will stop charing periodically. The battery lights and ABS lights will come on and the voltmeter shows around 12v as opposed to 13-14v. This seems to be random and can happen anytime, hot or cold engine, rolling or stopped, accelerating or slowing down. Any thoughts?