battery light not on but bat still dies??

ok i just went and got a brand new alt today had it tested there and broght it home and i put it in and i have no battery light but my alt is only putting out 12.03 volts i dont get whats going on this is the third alt i have tried my battery keeps dieing and i dont know whats going on at the post at the alt im getting 12.03 volts i dont know if any of the wires in the green plug have to turn anything on or what but nothing is happin dont know what to do next
please help
thank you
justin

Here’s a shot in the dark, have you tried to replace the battery?

yes I did. I also tested right at the post off the alt and still just got 12.03 volts could there be anything with the plug what is that for?? I am just so lost
thanks
justin

ok I think I found the problem I just had my alt bracket powdercoated I think that it is not grounding it self does anyone else think it could be this

^^^possibly. I would really check around before grinding away any of the new powdercoat. Sry though, not much of an electric guy. Have you tested the regulator? maybe its juicing up your batt too much and frying it? OR, maybe i sound like a complete ass. I don’t know, just trying to help:up:

why nismo??? anyways, i think you just found your problem, its not grounded due to the powdercoat.

well the nismo is for my 71 datsun 510 2door im building
something to play with that is rwd.
yes i ran a ground strap and the alt started charging so funny did not even think about self grounding.