RE: 2002 f250 4x4 7.3 diesel won't start cold?
Is your S/D a Calif. emmission truck?
CA trucks will have a glow control module, and nonwill have a glow relay.. If the glow system isn't working it can/will make for a very hard starting engine, more so in the colder temps.. If the block heater is plugged in, does it start normally in the AM's??
The glow relay (if equipped) sits just to the right (passenger side) of the engine dress cover.. Looks like a starter solenoid, two large lugs, and two small.. If module equipped, it's in the same area, mounts to bracket and is a aluminum looking box with cooling fins.. The UVC harness/s plug right into the valve cover gaskets one per side and the harness's are wrapped in red tape.. The later 7.3's didn't have as much problem burning the UVC connections, but not unheard of..If the connectors are bulged or show signs of excessive heat on the 'outter most' pins (outter 2 pins on each side of each connector) than the connection/s may be failed..
If you crank for over extended amounts of time, you can overheat the starter and damage it.. Could be as simple as the stater relay, or starter solenoid as well.. You might try jumping the solenoid on the starter direct to see if the starter engages/cranks..
The 7.3 needs to have 'minimum' of 100RPM to start.. If the batts aren't hot enough, or are at the end of their service life, coupled withvolt/amps drop with glow cycling ect. and cranking speed drops below spec, it won't start.. Each should be uncabled and load tested individually.. Even jump assist attempts with a donor with lower than needed available cranking amps, and less than quality cables, make for a hard/no start..
05 F250 C/C FX4 6.0
1969 Firebird Trans Am
2003 Hayabusa GSXR1300