Hi Alex,

Your directions are to add extra high beams and very sketchy, they don't include
a fuse which makes it a landmine loose in your car. I'd forget those directions.
Volvo uses a 15A fuse for foglights. This should be tailored to the current requirements of whatever lights you add.

Your relay has numbers on the base that seem to correspond to the Volvo and unversal relay pinouts. Maybe your relay conforms to this pinout?

30 = C Common (switch)
87 = NO Normally open (switch)
85 = Coil
86 = Coil

If there's a diode across the coil then it can be hooked up backwards.

You can use this with the schematic I sent, at your own risk of course.

You can get these relays everywhere for short money and know for sure
what you have.

https://www.superbrightleds.com/cat/off-road-lights/page/1/

Here's the relay you want. It has the diagram and pinout. $2.95
The extra pin is the NC normally closed switch contact, that you wont be using.

https://www.superbrightleds.com/moreinfo/work-light-accessories/12vdc-3040a-5-pin-universal-relay/1667/3844/

They have a pigtail socket for it $1.95 and / or you can connect with spade lugs.

While you're looking around you might decide to install high power LEDs, far better than those antiques that you're struggling with, and the price has dropped way down so that they're affordable.

Bill