Yeah, the rotor looks OK, yet its 2.0 ohm resistance across the slip-rings is considerably lower than the 3-4 ohms that you have experienced, and that is what is causing me concern. Unless I can find the specifications for this particular alternator, and they correspond to about 2.0 ohms for the rotor field coil resistance, then I'm afraid that the RE72 regulator that I've got on order isn't going to fix this thing for long.Charlescrown wrote:From my experience little goes wrong with the rotor. I have seen one go short to ground easily picked up by measuring resistance from a slip ring to the rotor shaft. Usually around 3-4 ohms resistance between slip rings for a lot of alternators. Even if the regulator is faulty (which is my guess) the rotors resistance will controll the current and prevent damage occuring. As prevoiusly mentioned a look at the colour and a smell should tell you if there is a problem. I did have a regulator that only went short to ground after the engine was turned off and that was obvious by a hot regulator when it should have been cool.
Joe.