my vehicle wouldnt charge so i replaced the alternator, and still wont charge, check relay , and checked gauge on dash, what do you guys think it might be? im thinking ecm? if ya'll get back to me as soon as possible that would be great thank you
PCM does not control the alternator. If it's not an "infant mortality" alternator, it's something in the wiring. It would be interesting to check the voltage right at the alternator output after the glow plugs have cycled off, and compare that with the voltage at the batteries.
You are waiting for the glow plugs to cycle off, and checking then, right?