My 1975 450 SL will not start. It cranks good, so I checked the fuel at the injectors and found I am not getting gas into the engine compartment from the fuel line. I think in the past when I turned on the ignition key I could hear the fuel pump pressure up (I could be dreaming here as I don't know for sure as it has been awhile) and now I cannot hear the pump. I checked the fuel pump fuse and it is OK. I loosed the clamp on the outlet of the fuel pump and fuel started dripping out so I tighten it back up. I then removed the two wires attached to the fuel pump and turned on the ignition switch to check for voltage and had none. Looking at my Chilton's repair book it mentions a "fuel pump relay" however I can't seem to find that. Does anyone know where the fuel pump relay would be or have an idea where else to start checking?