Ok so I had my idiot brother inlaw replace my heater core without taking the dash out all my lights except dash lights worked before... now none work and over half of my fuses in my fuse box dont have power to them plus i went through him messing my car up for no reason cause I still dont have heat could anyone please tell me something to try an do to fix these problems? Thanks in advance

 

Car information is required for all tech threads. Click the Rules link in my signature.

Check whether the hazard lights switch is unplugged.