Solved: Replaced the alternator, not fully tested because a tree fell on it

These alts aren't cheap and don't look easy. 2009 G37x 86k miles AT. The brake and battery warning lights have been coming on and off for the past month or so. I've been scalping forums trying to find exactly what could be wrong before swapping parts and its really a mixed bag, the obvious grounds all seem solid. I drive this car under 50 miles a week so it often isn't on my mind but I think today will finally make it easier to diagnose. I did replace the battery back in May.

My typical drive would be the driveway -> 4.5 miles of 60mph, .5 miles of 30, then the opposite of that on the way home. The warning lights would typically go out in the 30mph area, usually accelerating from a stop sign.

However the last few days have been different.

I stopped to get gas on my way home yesterday and noticed it started a little slower afterwards and then stopped at a store and it started very rough.

Then today was really the killer.

1) The car started clean after work, drove it about 200 feet to a different work parking lot and turned it off
2) Started up again just fine, going about 10-15 mph on my way out the gas pedal stopped responding
3) I put it in reverse and it idles back to my parking spot where I shut it down, oil is solid.
4) Started up again fine, idled fine, drove away like nothing is wrong
5) Maybe five minutes after going 60mph the gas pedal stopped responding again, I didn’t notice any other electronics shutting down or dimming. I pulled over and put it in park for maybe a minute leaving it on.
6) Drove home the rest of the way fine and noticed a new noise.

 

Any updates?

 

I'm sorry, I'll shut this down. It was the alternator. I found one from a junkyard out of a 2014 Q50 with 16k miles on it for $42, it was a pain to put in but I am fairly certain it was the issue. I only drove it probably five miles after the replacement but I didn't have any of the bad lights or scraping sounds.

And not kidding the next time I went out to drive it there was a tree down on top of it (10-12-21), I'm still waiting to hear back from the insurance company. I bought the car with a salvaged title in 2018 and a deer hit me within a month after that and it was repaired iffy. I have only put 13k miles on it since then and this is what I get 86000 miles. I think this car is cursed.

 

Hopefully they'll just total it instead of trying to fix it.

 

Honestly I don't want this type of car to be a beater so I'm kind of hoping that will be the case and I don't get screwed over. Ever since that deer ran into me and I got the so-so repair job I haven't been super happy with it. I showed the repair shop and the insurance company the things that weren't right and they basically said too bad because it has a repaired title and you don't have proof of it's condition right before the incident. I have never even bothered trying to sell it either since I'm an honest person and would point out every minor flaw there is to anyone interested.