Here’s the situation:
I recently replaced the alternator on my 2007 Kia Optima 2.4L after the battery lamp came on, and I confirmed that the alternator wasn’t outputting any voltage. Unfortunately, the new alternator didn’t resolve the issue—there was still no voltage coming out. I later realized that the new alternator had a slightly different pin configuration. The old alternator had a 2-pin setup, while the new one (from a 2008 Hyundai Sonata) has a 3-pin setup, though they use the same connector. I had mistakenly connected the lamp wire to the sensor wire. After switching the wires, the battery lamp turned off, which seemed like progress.
However, the car eventually died due to low voltage because the alternator still wasn’t charging the battery. I checked the sensing wire and found no voltage output. I also checked the control wire but couldn’t detect a PWM signal with my multimeter.
I’ve verified that the alternator fuse is good and that the connection from the alternator output to the battery is solid.
At this point, I’m confused and unsure of what’s going on. The only thing I can think of is that the car’s computer might be refusing to activate the alternator, but the ECU hasn’t shown any signs of damage and doesn’t have any other issues.
Has anyone else faced a similar problem or have any ideas on what might be causing this? Could it be something I’ve overlooked? Any advice would be greatly appreciated!