Ways to bypass Fuel Pump Relay on 300E - Mercedes-Benz Forum

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post #1 of 3 (permalink) Old 06-15-2009, 05:21 AM Thread Starter
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Question Ways to bypass Fuel Pump Relay on 300E


I do know this information has been posted here before but I've searched for an hour with no luck so hope you don't mind me asking here.

My 1998 300E has the imfamous non- start problem - sometimes fuel pump kicks in first try usually I have to go back an hour or more later and try again. I had similar problem on last car - 230E - and that time local garage fitted a bypass from the fuse box area to a fuse holder so when fuel pump didn't work I could insert fuse and get it running so I could start car.

We want to do same with this but he's not sure what he needs to do on this model and I am hoping someone here can help.

I know you can bypass by covering pins in the relay but doing it via fuse box or something in that area is preferable.

Please reply if you have any info on this as I miss driving my merc but need the bypass option so I won't get stuck if relay goes funny.

Thanks for reading.
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post #2 of 3 (permalink) Old 06-15-2009, 10:39 AM
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normaly it's jumped between pin # 87 & 30 - this is for test only..
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post #3 of 3 (permalink) Old 06-15-2009, 09:35 PM
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Resolder the fuel pump relay connections on the foil side, especially the large pins of the relay.

Near Manassas Va. '65 220S, 2006 Ford Crown Victoria Police Interceptor, '99 Volvo V70, '72 350SL 4 speed

Not part of the in-crowd since 1952. It's BRAKES not breaks. You break a bone, use brakes to stop your car. /rant

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