420SL wont start fuel pump not working

[pikeyboy]

hi not sure if any one can help but my girl friend has a imaculate low milaage 420SL. thing is I fitted a new battery on saturday and it ran and drove mint for fifty miles or so. I went to it sunday morning and it wouldnt start, the fuel pump isnt buzzing when you turn the ignition on. does any one have any suggestions could it be a common fault? is there a manual/wiring diagram avaialble, doesanyone know where the fuel pump relay is as i'm trying to track the harness back becasue there doesnt seem to be any power getting to the fuel pumps under the car.

thanks in advance
pikey

[sneijder]

Once you find the fuse box, the relay you want is item 116



If your car has factory air con, which is very rare, there will be two there.

HTH

[pikeyboy]

thanks very much ben, i'll have a look when i get back, i do hope its something simple like a bad connection or a dicky relay.

[will_uk]

Once you've located the relay it should be fairly easy to bypass it (for fault finding).

Have a look and check (wiring diagram if possible), but in the MBs that I've worked on (W201/W124 etc), it's been a case of bridging terminals 30 and 87, which allows the fuel pump to run continuously. Obviously don't leave it connected like this forever, but it's a good method of testing

You may be able to repair the relay if you can get it apart, they normally suffer from dry joints from what I've seen.

Good luck

Will

[pikeyboy]

still struggling with this one, it has no power at the pump when the ign is at position 2 ie ignition lights on and you usually hear the fuel pump buzz but if you crank the engine it fires up for about 0.5 seconds and theres power at the pump for a moment....any ideas? or does anyone know of a decent auto electrian / merc indpendent specialist around sale in manchester

thx
pikey

[sneijder]

A little out of your way, but Ian @ West Coast in Lytham gets my vote :

http://www.westcoastautomotive.co.uk/index.htm