Re: starting problem
Each connector on the valve cover has 5 pins. The two outside pins on each connector goes to the glow plugs. Test the glow plugs from the battery ground to the pin on the valve cover. Factory specs are from .6 ohms to 6 ohms are good plugs but anything over 2 ohms and the plug is living on borrowed time.
Also check the relay. When it is energized measure the voltage on each of the two large lugs to a battery ground. There should be less than 0.3 of a volt difference between the two.
96 F250 XLT 4x4, 4:10 gears, 5 speed, Tymar intake and HX hose, downpipe, pyro and boost guages, coolant filter, Luc clutch