Hello no name,

The lights on the door pillars were tricky to hook up the way Volvo wired it.
I used direct replacement LED bulb units that turned out to be high failure
items since they were flimsy construction mechanically and the Volvo sockets
have stiff springs that tend to destroy the early LEDs. What does work much better are the little flat card LEDs that come in a variety of sizes.

The flat cards (PCB's) have the LEDs facing in one direction. More Light!
These little LED boards have a short harness to mate with a variety of sockets
that also have a short harness. The pillar is then easy to install since you just reverse the 2 pin harness connector to correct the polarity.

It's better to remove the assembly to install the socket adapter and position the cards. a 24 LED card or two paralleled 15 LED cards easily connected with the harness connectors might fit as well. I didn't try since the light from the 15 LEDs is terrific. The early 9 LED package what you probably have, has most of the LEDs facing the wrong way. I estimate you get about 5X or more light from the flat card.

I think I used a 12 LED flat card for the pillars since there's less room
Its 29 X 22 MM vs 37 X 22 MM for the 15 LED card
There's a 24 LED card 44 X 29 MM that might fit the reading light assy., or could be used with the festoon socket for the trunk light.

These cards have two sided foam tape on the back so they can be stuck on to surfaces.

I ditched all my early BA9S LED's for flat cards that you can find at Ebay,
search "LED panel BA9S" , that should bring up a pile of options and cheap prices.

Good luck, Bill