Jeff -

I am enjoying the same problem on my 1986 244. I had thought it a problem related to having the high level brake light involved with the circuitry, but maybe it's not. Since you don't have that high level light, I have another idea.

What if there is corrosion or oxidation in a connector that's between the brake light and the BRWS relay?

I see two such connectors in my 1984 240 Volvo Service Wiring Diagrams book.

One is a nine-pin job located up in the corner where your lift toe points. The ppotitions are numbered. The wires are #1 green/red (fuel level), #2 red/yellow (fuel pump), #3 green (left turn), #4 blue (right turn), #5 yellow (brake light), #6 yellow (brake light), #7 blue/red (tailgate washer - 245), #8 black (back-up lights).

There are a lot of connectors and stuff where this one is, use the color form that list to ID which one you want. Clean all the connections.

Then check the connector on the circuit board that has the lower voltage.
The little box comes off easily once the lock is released. Make a note of which wire is in which slot, and then take out the one for the brake light and clean it and pinch it a little tighter.

Hope that works.

Good Luck,

Bob

:>)