PeachParts Mercedes-Benz Forum - View Single Post - Why oh why does my tail light bulb keep burning out?

JamesDean · #13 10-20-2015, 11:58 PM

Here is another good place to buy LED lights:

https://www.superbrightleds.com/cat/led-vehicle-replacement-bulbs/vehicle/1985-mercedes%20benz-300td--/37-3304--/

https://www.superbrightleds.com/cat/led-vehicle-replacement-bulbs/vehicle/1985-mercedes+benz-300td--stop+light/37-3304--965327/

Quote:

Originally Posted by vince77

And what is this 'cruise control' you speak of? I think I had a function-less lever labeled cruise control once...

The cruise control system uses the brake lights circuit as a safety mechanism. When the brake lights are in the off state the cruise control amplifier senses a path to ground and allows normal operations.

When the brake lights are on two things occur, the ground connection of solenoid inside the actuator is broken, mechanically disabling the cruise. The 12V signal also enters the amplifier instructing it to turn off.

When an LED light is installed it removes this path to ground and disables the cruise system as the cruise system.

If you're interested in restoring your cruise control system, drop me an email. I've worked on almost 800 units, the oldest of which is still working. 80,000 miles and counting in my 91 300D.