Glowplugs not working

burtcheca

farmer/cabinetmaker
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Yesterday, while I was in town, the car's light for the glowplugs in the dash did not light up and had a hard time starting the engine. Had to use a little puff of starter fluid. Looks like the glowplug circuit has a problem.

Does anybody have a diagram of the glowplugs circuit for the '81 Mercedes 300D? I can find out the hard way but it will save me some time and errors to start looking for the problem with the diagram in front of me.

Thanks.

Burt.
 

Hit Man X

Huffin Diesel Smoke
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Dec 20, 2006
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Texas
Yesterday, while I was in town, the car's light for the glowplugs in the dash did not light up and had a hard time starting the engine. Had to use a little puff of starter fluid. Looks like the glowplug circuit has a problem.

Does anybody have a diagram of the glowplugs circuit for the '81 Mercedes 300D? I can find out the hard way but it will save me some time and errors to start looking for the problem with the diagram in front of me.

Thanks.

Burt.



It is pretty simple, you know where the relay is located I assume?

One plug on it is to the glow plugs themselves. Main hot wire is obvious. The other is what activates the relay.

The four pin connector should be as follows:

Pin 1 - red with stripe is the switched 12V from the ignition switch
Pin 2 - violet from starter power block, right beside turbocharger area (you have to look, I have W126s and have not had a W123 in over a decade)
Pin 3 - blue runs to dash light
Pin 4 - brown is ground on Euro cars (think soil, earth, etc)
 
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