New Alternator Not Charging Battery? 1998 Toyota Camry

1998 Toyota Camry 2.2L, 4cyl

So recently my battery kept dying on me and I was unsure as to why. So, I took it to AutoZone and had them test the battery and the alternator. Battery was fine, but the alternator kept failing the test. They said my battery was at 91%.

So, I took this opportunity to get a new alternator and a high output one at that. I have a 1998 Toyota Camry and the place I brought it to said I could beef it up to 170A output. So, I did that since I have a car audio system. It was completely rebuilt with a new stator, bearings, brushes, etc. I also figured I would need to beef up my electrical system to handle the new power so I completely rewired my system with 0 gauge wire from KnuKonceptz.

This also includes me performing the big 3 upgrade of the alternator post to the positive battery terminal, engine block to ground, and negative battery terminal to ground. When I install everything yesterday, it all goes well. I check the battery at standby and it is at 12.4 V. Check it with the car running and it is at 14.6 V. Perfect! However, I drive for a bit, come back, and check the battery again while running and it is at 11.8 V.

I try it again this morning and it was outputting 13.8 V at idle, but still undercharging. What could be going wrong that I am not getting the proper output from the alternator?

TLDR: Battery kept dying. Checked it at AutoZone. Alternator is bad. Battery is good. Got new 170A high output alternator. Completed big 3 upgrade with 0 gauge wire. Battery still undercharging. What could be the problem?

After driving for a while with the engine warm, take a voltage reading at idle (probably between 600 - 800 RPM's). What do you get?

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