Insrument panel doesn`t work ,car door locks don`t work!

its definite that your old mechanic did not place everything in place. I would suggest that you just bring your car back to him and have him fix the problem he created. if you change his installations, he might blame you for the issue.

Check the switch module for disconnected.

if your speeking of none of the insrument light illuminating, but headlghts work, then it's the headlight switch that's bad,the headlights will go out very soon though, it basiclly stages down, partial burnout starting with insrument panel. not too hard to change though. abt 50 bucks for the switch give or tk a few

Dash board or gages

I assume the doors can be manually locked. The problem is in the electrical circuit. That means anything from a faulty switch (the lock / Unlock button) to a loose connection. If both switches don't work then look for a blown fuse. If one switch works and the other doesn't than remove the switch and inspect its connection. If it's ok then check the switch. If both switch and connections are OK then you'll have to remove the door panel and access the lock mechanism.

Check the ground for your rear lights. It's probably one single ground for all the rear lights, though I don't know that for sure. If it's not a grounding issue, it must be a loose power connection.

Check fuses?

Did AAA clean the battery cable connections when they installed your battery? Did you check the fuse for the insrument panel?

It could be just bad timing or a coincidense but I am more likely to think things are connected. If your gauges worked after jump starting your car, but not after AAA changed the battery, something changed or was left disconnected.

ask a tran shop...