Dodge Repair: dodge ram3500, fuel pump?

Question
QUESTION: I have a 1997 Dodge ram 3500, 4wd 8.0 litre, a few days ago I started it to let it warm up, it started fine then 15 minutes later it died. I got it to start again and it would idle for about 30 seconds then die. If I tried to throttle it up it would die. Now i can not get it to start at all. I have checked all fuses and they are in working order. i recently purchased a new fuel pump but am hesitant to replace it until I have checked all other possible solutions. any advice would be greatly appreciated. thank you for your time.
         Craig

ANSWER: Hi Craig,
Listen when you first turn the key to the 'run' position to note whether you hear the pump run for about a second or not. Normally is should do that. You may need to have a helper turn the key while you listen near the tank.
Second, try turning the ignition key "on-off-on-off-on and leave on", doing that in 5 seconds or less elapsed time. Then watch the check engine light and or the odometer window to see if either the check engine light (which stays 'On) begins to flash, pause, flash etc. in which case count the flashes before each pause OR a 4-digit number replaces the mileage reading in the odometer window. Either way would give us a fault code readout that would help explain why this is happening.
Please read the PS below and respond to it.
Thanks,
Roland

---------- FOLLOW-UP ----------

QUESTION: I've done the on off on off with key and know fault code or even check engine light. I even left the key on and purged the valve stem on the fuel rail and it is dry. Not even air comes out. No sound from pump either. Could it be froze up? It hasn't been over 25 degrees since it started?

Answer
Hi Craig,
While I don't have the manual I would assume the engine control system of '97 operates the same as other Chrysler vehicles where the fuel pump does run for about a second when you turn the key to run and then will start again when you try the starter. So if the fuse is good there should be voltage to the pump while cranking. If you have a voltmeter (or a glow light) check the wires at the tank for voltage. The 12V wire may be dark green white, and the ground would be black.
Thanks for the rating and nomination.
Roland