Similar problem - 95 Legacy - brake/shifter interlock solenoid will not activate.
<<<NEVERMIND ! this was just a combination of simple problems, Loose grounds, blown fuse, wrong wattage bulb in 3rd brake light (someone put in 17watt instead of correct 12.5w)>>>
<<<I'm going to edit in my discovered answers to my own questions>>>
I was having brake light issues. The 3rd brake light was blown out and the socket was melted.<<<edit(wrong wattage bulb heated and melted the socket!)edit>>> When I apply brakes the RIGHT taillight and brake light go out. <<<edit( the ground screw for two bulbs heated up and deformed enough to break contact! very hard to see it... this may have also been caused by the wrong wattage bulb in 3rd brake light ?)edit>>> ( I also found a loose ground wire on the LEFT taillight making the taillights dim. I tightened it and the lights got brighter) while checking the 3rd brake light I think something may have shorted in the bad socket and now the Brake/shifter interlock solenoid will not activate. <<<edit( simple blown fuse from messing with the socket with the lights on!)eddit>>>