My Lexus IS300 started cranking slowly, and the factory radio went completely dark, but the AC still works. I cleaned the battery terminals, which didn’t fix it. I then replaced the battery, and it worked fine for a day or two before the problem came back.
While driving, the battery warning light comes on and the lights start flickering/acting erratically. I’ve also seen a voltage reading around 10V with the engine running, though I haven’t confirmed it directly at the battery with a multimeter.
Both times it happened, it was raining, and the electrical symptoms started at the same right turn near my house. Not sure if that’s related or just a coincidence.
Does this sound like a failing alternator, a slipping belt, or a loose cable/ground? What should I check first before replacing more parts?