Car: 2009 Aveo5
Problem: Battery and brake light illuminate together. (Bad alternator)
Story (In a nutshell): Battery and brake light came on. Dash lights started to fail. Gauges started to fail. Engine stopped. Stalled on the freeway. Nice people helped me push to a hospital parking lot. Jumped. Started and ran for a few minutes then died. Repeated this about 5 times. Went to store and bought a new battery. Car started and ran but lights (battery and brake) remained on. Drove home.
What I've done so far:
- Checked all fuses - OK.
- Got a new battery.
- Removed alternator, took it in to be rebuilt, reinstalled rebuilt alternator.
- Tested wiring from alternator to battery - OK.
- Tested voltage running should be about 13.7ish volts but am getting intermittent readings of ~13.2v.
Existing problem:
It seems that the alternator works but there is something happening that "turns it off". While it is running, the engine changes pitch (like when the A/C compressor kicks in) and the voltage drops and the batt/brake lights come on. It runs like that for a few minutes then the voltage goes up over 13 again and the lights go off. Repeat...repeat...repeat. It also does it while driving. I tried to connect the problem to RPM but it seems random.
An electrical engineer friend says that there should be a electrical charge control module that regulates charging the battery. He's not a mechanic but says that's the way recharging works.
At this point, I have eliminated battery, alternator, fuses, and wiring. What else is there?
Is there a relay, fuse, ECU/ECM, or other component that I cannot/haven't checked?
I dread taking this in to a mechanic/dealer to get it diagnosed since I'm a po' boy.
Ideas?