Originally posted by plink49
As a side-note, I intermittantly get a bulb-failure dash light on my '86 300E and have for years now....it just seems to come on every 6 months or so and last perhaps 2-3 days and then disappear for 6 more months...who knows!
Your taillight rails are causing this problem. They get loose with vibration and loose contact with ground, setting off your dash indicator.
The same vibration probably seats them back in place, and the indicator goes back off...weird.