I'm not sure about the '86 but I went through a nightmare with my '89 and it's brakelights.

The Volvo has a large red can shaped Bulb failure warning sensor. Basically, if your head light is out you wil get an idiot light on your dash telling you that a bulb is out. This sensor is located above your left knee while sitting in the drivers seat. it has a spring clip holding it to the dashboard.

Well, an internal section of my warning sensor failed. causing me to have no brakelights AND no idiot light telling me this.

Yes I just looked in my Bentley book, the '86's have it too.

I traced the color wires back from my brake lights and saw where they are on the connector for this sensor, I soldreed a jumper right on the pins to the sensor to by pass it for the brakelights only. I suspect this because you aren't even getting power to the highbeam relay (it sounds like).

The headlight relay is a silver square relay screwed into your drivers side fender, under the hood.