Hi, I’m not a frequent poster but I’ve been really questioning this situation for awhile.

Over the Summer I worked at a camp, and I lent one of my coworkers my car last minute because his ride to an event he had the weekend off for flaked last minute. I was friends with the guy and trusted him, so I told him to just bring it back with a full tank of gas and it was cool. When he got back with my car, he told me that it was acting strange on the highway and took it to a local repair shop, where a technician did a full alternator replacement. He did not contact me about any of this until he got back, which I didn’t think much of at the time because we had little access to our phones during the day. 

He wants me to pay the majority of the $350 the replacement costs, but I have some issues with this. First of all, the car, even though it has a lot of mileage on it, had never had any issues with the alrernator before. He also didn’t make any effort to contact me, despite the fact that he could have reached the camp even without me having my phone on person. Also, a little while after the alternator was replaced, i had to have the serpentine belt worked on, which i’m suspicious may have been damaged when the repairs were done. Most worrisome to me, I’m not even sure if the alternator replacement was necessary. All my coworker said was that the car was “actig weird” on the highway and that he thought it needed to go to a mechanic. 

TLDR i lent a coworker my car and he had repairs done on it that i did not consent to and may not be necessary.

AITA for not wanting to pay for the majority of this?
