What causes this problem & how expensive is it to fix? on 2004 Volvo S80

Driving on hwy and left rear door open light comes on. Stopped & made sure door closed. Continued on way, light cae on agn, then service air bag come on, then dash lights went off and air conditioning went off, 95 degrees outside & power windows would not work. Very hot inside auto. Pulled over and cut car off and got out to cool off. Let it sit for an hour & got back in, ignition switch didn't do anything but tried again and everything worked fine except service air bag light stayed on. Drove 200 miles home and everthing worked perfectly???

Asked by for the 2004 Volvo S80
Electrical issues on this can can be difficult to diagnose because of the sophisticated electrical system. I suggest taking it to a Volvo Dealership or specialist only, and have them look at it. They should give an estimate up front of 1-2 hours to look into this for you.
Good Luck!
hi bret, how are you??