Do you have the Volvo Wiring diagram for your car?
The wiring varies between 4 and 5-door models.

Here's my hunch from your fuzzy description.
A better tally of exactly what's quit would aid troubleshooting, but from
what you say is dead, I see a potential problem with the Central electrical power ground 31/50. This is located at the fusebox on the firewall.

The wiring diagram gives a complete list of what ground paths 31/50 supplies.
Check it out and see if it's your list of dead stuff.

Each electrical component needs a + and a - supply, and all you need is
a loose ground or a ratty connection at 31/50 to give you that headache.

Bill