I have a 1981 380sl, the electric is a little screwy. The windows don't go down, the turning lamps dont go on, the brake lights don't go one, the brights don't go one, and the horn no longer works. I changed the fuses, still no luck. I used a test light, there was no power going to the fuse. Tested the relays, they have continuity. Could it be a ground? I'm stumped right now.