cold weather no start

[missingsc331]

a good friend of mine asked me to ask my friends here at sdd a question about his f250. he says that when it is around freezing his truck wont start unless plugged in, he had the glows checked by ford and found everything ok. any ideas? thanks

 

[JLDickmon]

well, there is a relay in the underhood power center that controlls the glow plug relay, that could be roached..

he can try Tbar's trick of jumping across the GPR with a jumper cable.. I've done that myself to prove my second replacement GPR bad..

 

[95_stroker]

Id second the GPR too. Easy check with jumper cables or a heavy screwdriver.

 

[missingsc331]

thanks a lot ... could you give me a link to this process?

 

[BJS]

the "easy" way to check it is by using a large screwdriver or jumper cables to connect the two large lugs which will provide power to the glow plugs do this for 30-60 seconds then try to start the truck.

The "complicated" way is to check the voltage on the two large lugs when the glow plugs are engaged there should be less than 0.3V difference between the two large lugs, ideally none detectable or 0.1V

 

[95_stroker]

thanks a lot ... could you give me a link to this process?

Dont have a link but can explain. Lift hood and locate GPR, its near the fuel filter on the right side, I believe there is a relay near there for the AIH as well on a SD 7.3L. So take a heavy long screwdriver and arc it across the two large terminals on the GPR and hold it for 30-60 seconds then hop in and see if she lights off nicely.

 

[missingsc331]

alright ... thanks again

 

[pete37922]

my mechanic said they roast easily !!!