Mercedes Benz repair: 1977 Mercedes Benz 300D-glow plugs, mercedes benz 300d, benz 300d

Question
Why don't the glow plugs turn off after it is started? The rails actually start to glow red after a few minutes when the engine is running before the glow plugs shut off.I purchased a pre-glow timer relay and installed it and it still does not prevent it from getting so hot the rails glow red.Did I get a bad one from the parts company?  What else could the problem come from? I am going through far too many glow plugs and have to replace the rails after they overheat so many times.

Answer
Excess volts/power issue.
It is easy to get the wrong relay.
If you have the relay and glow plug part number, call Phil to verify it, he will need the engine number or total VIN to look it up.
Or, you call him with your VIN and ask for the relay and glow plug part number and price, then check your parts for numbers.

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