So I was driving home in my 2006 Infiniti M35 and I notice my brake and battery lights were on. Pulled into my neighborhood and I lost acceleration but the engine would idle. I idled enough to get home and pulled into my driveway. Restarted the car and got acceleration again to pull into the garage (I'm on a slight hill). Got my OBD2 reader out and it said turn the key to on without turning on the car and so I did that and all of the sudden my radio started getting really quite and then loud again (like it was losing and regaining power) and my dash lights/navigation were flickering. I tested my battery and it shows 11.65 volts with the car off. The OBD2 reader didn't give me any codes. I was going to take the battery out and to autozone to be tested but I'm wondering about the alternator. I was having a power steering pump leak a month ago that was dripping fluid down onto the alternator and wonder if there could be an issue with it because of that?

Okay so I have an update. I took my battery to Autozone and they said it was like 14% and couldn't tell me if it was bad or not. It was under warranty so they replaced it anyways. Got it back installed and the battery light and brake warning light are still on but I'm still not getting any diagnostic codes.. shouldn't I be getting some if there is a problem with the alternator? I tested the battery voltage before install and it was 12.38V and while the car was running, I was getting about 11.8V. Not sure if that matters or not but was reading other threads and it seemed like it might. Autozone said they test the alternator as well. Any tests I can do to help me figure this out at home before removing it for testing?

tacomaguy20 wrote: ↑

Sat Apr 16, 2022 8:13 pm

Okay so I have an update. I took my battery to Autozone and they said it was like 14% and couldn't tell me if it was bad or not. It was under warranty so they replaced it anyways. Got it back installed and the battery light and brake warning light are still on but I'm still not getting any diagnostic codes.. shouldn't I be getting some if there is a problem with the alternator? I tested the battery voltage before install and it was 12.38V and while the car was running, I was getting about 11.8V. Not sure if that matters or not but was reading other threads and it seemed like it might. Autozone said they test the alternator as well. Any tests I can do to help me figure this out at home before removing it for testing?

The alternator generally won't cause codes, you'll just get low or no output. That 11.8V indicates zero output, and the generator light means the internal regulator knows the pooch is screwed. Replace the alternator. You might also have a blown alternator field fuse, but those rarely blow for no reason. Usually it means the alternator is crapping out and the blown fuse will recur.

Gotcha, thanks for the info.

I think I found out why my alternator died, the connector has cracks in the wires. Something probably shorted out.

tacomaguy20 wrote: ↑

Tue Apr 19, 2022 8:59 pm

I think I found out why my alternator died, the connector has cracks in the wires. Something probably shorted out.

Very common failure. They sell the pigtails all over eBay and Amazon, and your parts store may even have one on the shelf. One caveat, keep the splices at least 3" back from the alternator housing and never use regular butt connectors. The repair needs to be waterproof, so solder-shrinks are best.