I have a 1988 Mercedes SE. Last week, my left brake light was out. I took out the bulb and it was bad. I had to go buy one so I put the tail light assembly back on. Then both brake lights and the rear window brake light wouldn't work. I replaced the bulb and the fuse but all brake lights still don't work...Any ideas?? Maybe the brake pedal switch? How do you check/replace it? Thanks for any help.