I have a 1995 stock f250 with a 7.3 truck will not heat glow plugs or start replaced relay and oil temp sensor and cleaned sensor plug truck ran about a week and quit prob returned found broke wire on ground wire from computer to relay now have 11.9 volts to relay but will not close relay will close relay if you ground small - terminal to engine need help

 

Does the wait to start light come on at all?

 

no wait to start light will not come on

 

If the wait to start light doesn't come on its a sign of a fried PCM. Happened to me when I jump started my truck one time. Chased every other possibility before I found out the PCM was fried. Along with my do tuner.

 

PCM controls the ground to relay. Have you tested the glow plugs? Under valve cover harness ends that plug into VC gasket often melt from current if you haven't addressed that yet. Do you get tons of smoke when cranking cold? Is wait to start light, water in fuel light, & fuel filter light all coming on when key is turned on?

 

Oops, just saw the other questions about the lights and you said they were not coming on. PCM could be fried, but I would bet the maxi fuse for PCM in under hood fuse box is blown. If so and it keeps blowing every time key is cycled, LMK, I can lead you in right direction before replacing PCM.

 

all fuses are good have enough ground to read 11.9 volts on meter but will not close relay relay will close if I ground relay ground to engine block

 

engine is getting no fuel will fire on either but dies when either is gone

 

 

Definitely reconnect relay wire to it's original location. PCM fuse is the 30A Maxi in center row, closest to engine, you absolutely sure it's not blown? If it is, remove the fuel filter and look at heater plate below filter and you will see where a bare metal wire is soldered to plate (supposed to be soldered) in 3 different spots. If wire is loose, eg not soldered anymore, it is shorting to ground and it shares same fuse. Either disconnect wire inside or locate outside wire located on driver's side of filter housing that's connected to terminal with large rectangular rubber insulator. Will have to pry wire off with long flat blade screwdriver cause it's under the fuel pressure regulator on same side of filter housing. If you want to remove from inside, filter stem is plastic and LH threaded. Be careful, but removing the plate is fine and you don't need it. If the fuse is indeed fine and heater plate is intact, you need to scan for faults and if P0605 is present, PCM is probably shot. Now if you have a programmer or physical chip installed, same fault will come up. If P0603 comes up, ignore it, it's for low voltage for KAM at 1 time or another. I'm interested, LMK what happens.