starting problems

[DaddymacK5]

I have a 03 F250 and it will not crank.
Leading up to this in the past few weeks it was getting more and more difficult to crank and i had to start pumping or holding accelerator while turning over, and it would crank after 2 or 3 times, but now nothing, i pulled fuel filter out and there was plenty of fuel in bowl, i did notice small wire on glow plug (relay?) on top of motor was loose (this was replaced a few years back with larger aftermarket one) so tightened and turned key on and put test light on the 3 different studs coming off it and light lit on 2 of the 3, Are all 3 supposed to light?
Is there anything else i should try?
Any help is much appricated

[kaya@bernhausen]

try jumping the 2 large posts of the gpr for 5-10 seconds, then having someone crank immediately after