Hi! took my Honda accord 95 model to a car shop today, had the engine oil changed. Then tech starts the engine but there's a loud squeaking noise, tech had adjusted the d/belt. However, after running at 10km, engine starts to vibrate and RPM drops, then the engine stalled. Restarted the engine with aircondition turned off, no stalling, I tried to turn on the AC while the engine is on at idle, the engine vibrates and stalled. What seems to be causing this problem? please help

 

something is wrong, sounds like he overtightened the belt by a mile, take it back and have him fix it