barnettgreg6

this seems to be a common problem which I haven't figured out the true underlining problem.
My alternator charges my batter fine when running however when it is shut off it drains the battery. I suspect the internal diode is shorted and causes the battery to drain through the alternator coils back to ground.
Testing this theory using an amp meter I was able to record almost 10 amps of current flow. When i took the alternator in for testing it read good , however after proving the short with an ohm meter connected to the terminal and the case, they replaced it.
This solved the problem for a while, which has now returned, Luckily Advance auto has a good return policy as this will be my third alternator within the year.
So my question is what dictates how much or how hard the alternator needs to work, I think this could be the root cause. A GM mechanic told me that the computer controls the charging rate, would I have to replace the alternator and the computer? anyone else have a similar issue on a 2004 Chevy?

danielclover72@gmail.com

I’ve been having the same problem with my Silverado thought it was the battery so I bought a new battery and an alternator just in case I was wrong. I’m sure hoping that after the alternator is installed that the problem goes away. Thank you this actually helped me out big time.