which I could ask of a real mechanic on Monday but it's driving me to distraction now so maybe one of y'all have a more informed opinion. First the backstory: Tuesday last, on the way back from Memphis, my AC went hot for more than an hour, but eventually got cold again; Wednesday evening the vehicle (an '07 Saturn Vue) started making a rubbing noise which my brother-in-law incorrectly guessed about the source of; Thursday i go to my mechanic and he determines that the AC compressor is going out, note that it will either just quit - or it will throw the main belt in which case a lot of stuff, "power steering, alternator, and so forth" would stop working. That would obviously be bad. Upon research i determined I'd have to spend an extra $200+ to buy a new compressor rather than gamble on a used one from a salvage yard, and so informed him I'd try to get my hands on a used one and set up a time next week (also got quoted a stiff price for the labor) Friday, oddly, the noise stopped and I thought "well then, it just died, no bigge" BUT my battery light came on - uh oh. Go to O'Reileys, put the tester on and "it says the voltage regulator is bad, your alternator is going out" Well shit, that thing is only 2 years old. Can get a used one 30 miles away but have to bring the old one...scheming how to get the old one off and their to get a replacement while stopping for a small errand on the way home...but damn, thing won't start! Too late. Call AAA, tow it home. Resign myself to having to buy a new one, line up an in-law who's done auto work for me before to put it on this morning. Done and done, all good. and oh by the way (so I thought) the belt was broke and he had to replace it while he was working. Fine, so be it. of course, with a new belt on when we go out, the noise returns - that shit's annoying, gonna have to break down and replace the compressor anyway - go in the store, come out, noise is gone! Also.... Battery light is on again. O'Reily's - same diagnosis. What are the odds!!! Did I get a bad alternator? Did the compressor somehow kill the alternator? Anyway, go straight home while you can! Investigate.... belt is broke again. Clearly the busted compressor is breaking the belts. So I'm going to have to get that used one, and another belt, and pay dude to go right back in where he was this morning and swap them out... Shit. BUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUTTT............ Here's my question. One of three things happened this week: 1. the compressor and the alternator just coincidentally went out within 2 days of each other OR 2. the jammed compressor somehow fucked up the alternator and ruined it OR the original alternator was never bad, and the broken belt (which I was unaware of since I still had power steering which I'd been told would be a sign it broke) caused the meter at O'Reiliey's to falsely identify the voltage regulator is bad. One seems highly unlikely is Two even possible? (part one of my question) and if it's not, isn't it very likely I can go back to the old alternator and take the new one back for a refund since the old one is probably fine? Whatcha think?