Headlights flash with brake lights!

[standupmon]

My just acquired '96 model 900 has a peculiar trait - whenever I apply the brakes, the headlights come on (and go off) simultaneously with the brake lights. I have taken to driving with my lights on all the time so people don't think I'm flashing at them. Anyone know what's going on with this?

[gcgreg]

Possibly wrong bulb in one of the brake light sockets. It can happen if someone jams a double-filament bulb where only a single should go. Can also be a bad earth wire, causing brake lights to find -ve via park lamp.