Update: alternator died on a 2016 Civic at 11pm in the rain, and the tow guy tried to sell me a battery
Last Friday around 11pm my 2016 Civic just shut off at a red light on Route 9 in Poughkeepsie, dash lights going crazy before everything died. I checked the battery with my multimeter and got 11.8 volts, so I knew it was the alternator, but the tow driver kept insisting I needed a new battery for $180 on the spot. I told him no thanks and had him drop it at my shop, where I pulled the alt and found the bearings were toast at 98k miles. Ended up doing it myself Saturday morning for $140 in parts. Anybody else have tow guys push stuff you don't need, or is that just my luck around here?
11.8 volts at the battery with the engine off doesn't really tell you much about the alternator, that's just normal-ish resting voltage for a weak-ish battery. A better test would've been checking voltage while it was running, should be 13.5 to 14.5 if the alt is charging. The bearings being toast at 98k makes sense and you prob saved a bunch doing it yourself, but just because the shop agreed with you doesn't mean the tow guy was flat out scamming. Those dudes carry batteries on the truck and get a cut, sure, but a dead car at 11pm in the rain often does just need a battery or a jump. You already had a multimeter and knew what you were doing, most people calling a tow at that hour don't, so he's prob used to pitching the easy fix first. Not saying he was right, just that it might be less of a scam and more of him guessing at what usually works.