PeachParts Mercedes-Benz Forum - View Single Post - Is this normal? 1983 300D odd startup dim lights

pawoSD · #2 12-26-2010, 10:16 AM

That means your car likely has the Bosch afterglow glow plug relay on it. When the car is started the glow plugs remain energized (drawing over 50-60amps) and dragging down the voltage of the electrical system for a few mins (its actually about 3 mins) then it clicks off and everything returns to "normal". The original alternator on these cars is not strong enough to counteract that load, especially if other things are on too. Completely normal. Solution is to install a higher output alternator. I have an 80A unit on my car and above idle it can handle most of the need so there is minimal voltage drop. A 90 or 100+ A unit would easily handle it all.