Mercedes-Benz: Fuel Pump Problems

I have a 1985 500 SEL. The fuel pump went out. I took out the whole assembly.
I replaced the pump and filter. I have hooked everything back up, and now it
wont start. I belive the pump new pump is working because I had a leak, and I
re-tightened it, so it lends me to believe the pump is working properly.
Anyone have any suggestions as to what could be the problem?

I knew it was the pump because it was buzzing very loud, and the car was
hesitating on me, and I had to have it towed. Thanks

VIPERS969 wrote: 

Put a 12 V lamp or a buzzer over the fuel pump contacts. If the relay is
working properly the lamp goes on for about 10 seconds after switching
on ignition without starting the engine.

If yes, check the pump and properperly fixed electric connections again.
Check the pump motor independently using a 12 V source.

If not

check the fuel pump relay. The high current of a fixed or hardly working
pump motor may burn or desolder the relay.

--

Roland Franzius