Pins #2 and #3 are suppose to have voltage to them. Pin#1 may have the 12 volts because you have it disconnected. If there is a fault with the charging system the PCM will set a fault code if it is something the computer sees as an issue. If there are fault codes for charging system faults post them on here to get an idea as to what is going.
What I would recommend you do first is a voltage drop test across the battery cables to check for high resistance. Using a digital volt meter take the positive lead and touch the positive cable terminal (note the battery post). The ground lead touch it at the alternator battery cable terminal. A good cable will measure under 1 volt.
Next take the positive lead and touch the battery ground cable terminal. The ground lead touch a good ground point like the alternator housing (the metal part) or any where in the body that has metal. A good cable will measure under 1 volt. So for example you measure the positive cable a value of 0.02 volts that is good. And on the ground cable you measure 2.4 volts then the ground cable has high resistance. Dirty terminals can do this. Sometimes the other end of the ground cable could have corrosion on the block side.
If both cables read under a volt and there is no fault codes then I recommend you buy a new alternator vs. Having the same unit rebuilt. They are not cheap but the new alternator will come with the voltage regulator built into. Some parts store brands are no good either so buy a premium brand like Remy, Delco or OE. Hope the info helps and let us know on the readings or if the premium brand alternator worked.
Aug 28, 2019 at 10:35 PM
