Fuel pump running when ingnition ON, 280 SL

Asked by Feb 10, 2017 at 04:56 AM about the 1982 Mercedes-Benz 280

Question type: Maintenance & Repair

280 SL W107.042 US model from 1982
The fuel pump is running when the ignition is tuned ON, and obviously when the engine is running.
As per Chilton's guide, this could come from a defective safety switch, or from a stuck pump relay. Am I correct?
Should I repair it or leave it as it is?
Many thanks from your help
Pierre Miossec

2 Answers


Leave it alone. The fuel pump is suppose to run and prime up when the key is in the on position.

Thanks for the quick reply. Just read the Chilton's saying "the pump will only run if the starter motor is actuated or if the engine is running" Thus my question.

Your Answer:


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