I got a 97 V70 a few weeks ago, and just noticed the front passenger speakers aren't working: having never messed with audio stuff, I don't know where to start the troubleshooting.
The car has a SC900 with the Dolby Prologic
The front passenger door, the dash and the dolby speakers aren't working at all (no buzzing or anything). Center and rear are fine
The previous owner added 2 speakers in the boot with some janky wiring

Could all three speakers be dead, or it sounds more like a connexion issue ? What should I check ? I'm not sure what to do since there's so many wires, and getting to the dash speakers seems quite hard
I have a multimeter and I'm not scared to take panels off, I just need a tool to avoid breaking clips
Thanks for your help









