How can I find the problem for no fuel getting to engine?
on 2000 Mercedes-Benz S500

I replaced the fuel system relay and there's still no fuel getting to the engine. What is my next step to troubleshoot this problem?

Asked by for the 2000 Mercedes-Benz S500
test pwr to the fuel pump then test fuel pump
How do u test the power for it? What, if any, tools are needed to test it? Thank you kindly.