I have a 1997 Volvo S90 i just bought used recently. The passenger side parking light does not work but the directional does and its ran off the same bulb? Then the other issue that the back end lights have issues as well. All 3 of my brake lights work fine. But 2 bulbs on each assembly do not work specifically my tail lights. I tried new bulbs that wasn't the issue and then i tried switching the Assembly around and those all worked fine as well so its some type of electrical issue. I then checked my relays and fuses and those all seem to be fine as well. My L main relay for my head lamps in the 2nd fuse box under the hood had the prongs gone in it so a relay wouldn't fit in it but my headlights work fine so that doesn't seem to be the issue. Really need help with this i appreciate it thank you.

 

I once had some crazy light issues for turn signals, etc and it turned out to be a bad diode in the Hazard Switch. Replaced the switch, which pulls directly out of the dash with a pick (no fasteners) and all problems solved.