I'm now on my third brake light switch over the last 12 years in my '71 280SL. The last one was installed in 2010, and I was reminded recently while driving that I had no brake lights. Getting behind the brake pedal and flicking the little white button on the switch got them working again; however, a few weeks went by and they're out again. All of these switches were purchased at an M-B dealer. Any thoughts?