Hi. Recently I’ve had some issues for a week or maybe almost two now and I wanted to see if I could get some advice or suggestions and commentary for my issues to get an idea. My 09 CRV LX has a clean title with only one previous owner and I’m a first time car owner. My issues started a week or two ago when I attempted to start the car and was greeted with a ticking/buzzing sound and the lights on my dash and radio were flickering and the car wouldn’t start. I tried starting the car two more times but the car still wouldn’t start and the lights on my dash wouldn’t come on. I got a jump after that and drove to my local Walmart automotive shop where I disconnected and took the battery in to be tested, which gave the result that the battery needed replacing. After I got the new battery and installed it, the car seemed fine for a day or two when suddenly, my partner who had my car while I was working, told me the engine light came on in the dash. She and my dad took my car to the local O’Reilly’s for a scanner reading which came back with a P0507 code for a higher than expected idle. On the paper, the suggested solutions were to replace the idle air control valve (IAC) and to clean the throttle body on my car. My dad and I proceeded to do just that after some research, and noticing that the car’s idle was rough and the mileage range was decreasing from my average usage, on how to access and clean the throttle body. We then started the process of accessing and removing the throttle body of the car when during the process after a bit more research and from our limited understanding, the 09 throttle body was an electric throttle body with a sort of IAC built into the throttle body and an autozone employee telling us the IAC is non-serviceable. We still cleaned the throttle body thinking it would work anyway and solve the issue. After reinstalling it, as well as changing the spark plugs and engine air filter, we started the car back up after reconnecting the battery. The car started but the rough idling was still present in the car and we seemed to notice that there was a sort of whistling/hissing sound coming through the AC vent even though the AC was off and the engine light back on for the same P0507 code. We took the car for a drive for a bit to see if that would help the computer relearn the idle position and I also had a mechanic perform an idle relearn procedure with a plugged in tablet to the car computer. The procedure seemingly helped and the rough idling and the whistling/hissing was gone and the idle felt good again and the mileage range back up to normal. The car was driven for a few days again without issue until the night of Saturday February 1st 2025 when I noticed the car was slightly roughly idling again and the whistling sound through the AC was back. Interestingly, the whistling sound would go away with the acceleration of the car. On Sunday, Feb. 2nd in the morning, I tried starting the car but the ticking sound was back and the dash lights and radio were flickering again and the engine would not start. I tried two more times which led to the same result of the car not starting, so I got a jump on the car and drove home. On the way, the idle was still rough near the stop signs and in park but the whistling hissing sound would go away while in drive. After that, I did not attempt to start the car until Monday, February 4th. When I tried to that Monday, the car had no power in the dash or lights or radio and the engine made no attempts of starting. I tried a couple more times with no luck and then left the car off for the remainder of the day. On Tuesday the 5th, my uncle came and gave me a jump and after leaving the engine running for a bit, where he took note of the rough idle and car feeling like it wanted to stall as well as the engine shaking some, he plugged in a plug in to test the battery and alternator tester into the cigarette outlet. The results on the plug in indicated there was an issue with the alternator overcharging and suggested an alternator replacement. I had a mechanic take out the old alternator and installed a new one. After the installation, we jumped the car again as the car was still dead and let the car warm up for a bit as we got done at around 9:20 in the evening. We noticed though that the car once again had a rough idle and the whistling sound coming from the AC vent again, but by this point the mechanic left after suggesting I leave the car running for a bit so the battery would recharge with the car on and alternator replaced. I left the car running a bit more and even pulled out of my driveway to reverse the car into it. While driving, the car felt like it was wanting to stall out and out of nervousness, I turned the car off and checked the engine. I placed my hand on top of the engine and it felt rather warm, but I wasn’t sure if it was normal or not as the temperature gauge in the car did not indicate any overheating. I have not touched the car since. Sorry for the long post, but I wanted to be detailed with the work we’ve done to see what advise I get. Please comment down any advice or suggestion you may find as I’m not sure what to do now and I’ll post updates accordingly.

UPDATE 1. It’s the next morning now and the car will not start. I inserted the key and turned and no lights came on and no engine sounds.