So my car almost died on the way home the other day (lights flickering, lose of power), but I managed to get home. But when I tried to start it the next day, the battery was dead. This same thing happened to me before, drained my battery out, and we swapped that. It ended up being the alternator, so I got it rebuilt at a battery-alt-starter shop. Unfortunately they are no longer in business. So I took it to Les Schwabb (local tire/battery shop) and they said the battery is fine but there is a problem in the "charging system". They're diagnostic machine is pretty basic I guess.

My question is, is the "charging system" just the alternator or more? I did search the forum, but couldnt find a direct answer. Any help would be great, thanks!

Does anyone know if the alternator harness is the same on the highport and lowport?

Ive got this same exact problem going on right now....yesterday I changed out my alternator for a "new" one. It turned out to be bad since I ended up stranded on the side of the road. Put the "old" good one back in after having it tested and battery recharged n tested as good...drove it from salem to corvallis ~40 miles during the day.
Tonight I tried to go to the store and got about 4 miles, headlights on (using hella 80/100s, not that it should matter) get a low voltage warning, bust a U-turn car dies in my parking lot...any ideas? Its setup exactly how it was running for the last 30k miles...now it wont even go 30 miles.

check the continuity/resistance with a multimeter between the output terminal on the alternator and the positive battery terminal. I tried two different alternators when I thought mine was busted just to find that the "charging circuit" wasn't complete, because these wires run in the loom around the front of my engine bay (fwd n14) and it got squished when the new motor was put in.

I've had to replace my alternator 3 times now. everytime the battery and ebrake lights turn on (which usually mean its the alternator not charging the system). But when i actually got the charging system scanned it said that the diode was bad. unfortunately, the diode is built into the alternator so it had to be replaced. Another thing too is that the the alternator for the sr20 is used in some mitsubishi's and another type of car. So make sure with the parts store that you have the correct part number. (usually good idea just to go through a nissan dealership only so you know its new and made for your car for sure)