From the Good Green Book Volvo and the new features for 1986, the year of the Big Plastic Head lights

Still points back under the Hood and the Voltage Distr block and the wiring from the other places and here is why.

The radio going off points to the Yellow Black wire from the Ignition Switch to the fuse panel 2. From there there on Fuse 1 is a yellow wire that goes to the Light Switch Terminal X. But that Voltage on the Yellow Black Wire comes from the Dist Block to the Ignition on the Red wire. But if that was bad, you would not get the car to start. So that gets ruled out.

There is a Red Wire from the battery that come into Fuse 6 of Fuel pump fame and that goes out from fuse 7 on a Gry/Red Wire to Pin 30 on the Head light Relay. And that comes from the Voltage distribution block. But you would not have voltage on the fuel pump and the car would not start and that rules that out.

There is one common voltage to both the high and low beams and that connects to the under the hood and you guessed it it comes from the distribution block to the High Low Relay under the hood. It goes to Pin 15 and there is a jumper (Blue) that goes over to 81A. If that was getting a bad contact the relay would not close because the voltage would be missing. If you have not light at all, it almost has to be either the coil inside the high low beam relay is bad or the voltage is missing on pin 15.

Trying to Scan the good green book now to help you out.

Regards,

Paul