I thought I fixed this problem two months ago.
For some reason my car is losing power. The battery warning light lights up and all of the lights on the car begin to dim.
I thought I fixed the problem by replacing the alternator back in November, which everything went back to normal when I did.
So what the fuck could be the fucking problem? The battery is three years old, but it's been tested as holding a charge.
3 year old battery I would go ahead an replace it. They dont last worth a fuck in the desert. Other then that I cant really help, electrical is my final frontier. thats where I would start though.
Here is something to try,
Charge your battery with a battery charger (the kind that runs on 120volts) then start the car. If your battery light comes on immediately, it's a problem with the alternator or battery or both. If it takes a while for it to do it then you have a very large load on the electrical system somewhere (i.e. A short)
But I'd put my money on the battery. Try replacing that first, it's not a bad idea anyway.
1. Acquire a decent multimeter
2. Check battery with multimetwr car off, should be like 11.9-12.2v
3. Start car, do same test. If charging, you should be something like 14-14.5v across the battery.
4. If not, use continuity on your multimeter and check from the alternator power out to battery positive. A beep confirms the connection is good. Sometimes there is a inline fuse between the alt and battery that can burn out.
If your alternator is working, I would follow other anons suggestions. Do a battery health test and look for drains/shorts.