I have an 05 expy with 86000 miles. It has been running fine. I get to work run some errends and park it for the nite. (It was raining when I was out) Next morning I turn key and it just cranks and does not fire. After reading a bunch of post I can see it is not safe to assume right away that its the fuel pump. What should I check first? I am checking that mod above spare tire today. I see a few people talking about a relay . Where would this be located ? If fuel filter is clogged would it prevent the fuel pump from running? When I turn the key I hear something humming at the fire wall behind the air filter then the gas gauge moves but dont hear ful pump. I checked fuse #12 and it is fine. I also checked the inertia switch. Any suggestions on what order to go in troubleshooting and how to pinpoint problem and if it is indeed the fuel system would be grateful. Where is fuel filter located? Thanks in advance