Ford: Fuel System Problem, fuel pumps, gas tank

Question
I have a 1994 Ford F150.  I usually run off of the front gas tank and keep a little in the back for when I get low.  Last week, I took off and drove a bout 25 minutes, then parked for 2-3 hours.  When I went to start the truck, it would not turn over.  I flipped to the rear gas tank and it started just fine.  I got going down the road and flipped it over to the front and it died immediately. Since then, I can only run off the rear tank.  Are there two fuel filters on this truck?  I only see one.  What else could be wrong?

Answer
there are 2 fuel pumps in the truck... (There is one per tank... ) There is also a diverter valve that joins the 2 tanks to one fuel line... the first thing we need to figure out is if the fuel pump working. switch the front tank on and turn the key to run... (You'll need a helper for this because the rear tank pump will most likley be on also...) let me know if you hear the pump ... it wiell sound like a humming or a whirring sound...) let me know what you get...