Get the fuse box ad relay setup checked by good electrician, it may be possible connection to Alternator is conged off and its quite tricky to catch by yourself, unless you know car diagram and have multi meter.
AC filter condition will tell that. When tech removes it he can air clean and see if it can be refitted or not. Ethically after 2 - 3 years or 30k - 40k km u shud change that.
Go for original OEM filter they are the best.
Remove rear seat back side and access the boot, it must have a small manual lock/unlock clip or button press that latch and it will open and you can diagnose the reason for this jamming. Cud be moisture, put plenty of WD40 and keep close and open few times.