bravee

Octavia 2 1.9 tdi. I got the car 2 weeks ago and the turn signals weren't working at all, hazard lights worked fine. Fast forward today and i put the battery in (i took the battery out cause i didn't need to drive it) and the turn signals worked but only the right one did, if i switch to the left the right one started working, basically they didn't work properly at all. I took it to my service and i changed all the filters and the oil, i started up the car and now everything works fine? I really hope it continues to work, but what if it doesn't, where should i look? Thank you