Mercedes Repair Questions? Ask a Mechanic for Answers ASAP
Hi, my name is***** this could be a bad relay or possibly a bad pump. First you should replace fuse 7 in the trunk in case it is making a poor connection at the tips of the fuse. Next you can try another relay or you can bypass the relay to see if the pump works. To bypass the relay you need to remove the relay and insert a fused jumper lead from terminal 30 to 87 in the relay connector. If the pump doesn't run you should verify that there is 12V at your jumper lead. If you have 12V at the jumper and the pump doesn't work you will need to replace the pump. You could also try resetting the top control module by disconnecting the negative battery cable for 30 minutes.
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