Well, I took my car (2009 Mazda 3 GT, Auto) to a highly reviewed shop nearby to have some routine maintenance done. They replaced the brakes (new rotors) in front, did a transmission flush, new air filters and an oil change. When I picked up the car, I noticed the car door ajar light was on even after I repeatedly assured myself that every door was latched tight. Also, the auto headlights no longer worked and the power lock on the doors did not work. I told the technician right away, and he said that they are probably just frozen (note: this visit to my local mechanic coincided with a fierce arctic blast and the temperatures have barely climbed above zero in the last 4 days). If things didn’t change the next day, I should contact them. Well the next day I needed a jump from my neighbor. I thought perhaps the door ajar light was a slow drain on the battery, but then I couldn’t start the car just three hours later. So, I went ahead and got a new battery, as mine was four years old and a gas station nearby had Interstate Batteries on sale for $69. I had hoped that connecting a new battery would reset the electrical system and fix the other problems, but no.
Any thoughts on what could be causing this? Should I never trust this mechanic again?