I have been having some problems with my truck for awhile now and I took the driver's side apart again today to try and figure out why my glow plugs are not working.

I have 10-12 volts on each of the boots for the glow plugs when I turn the key to "run" but noe of the glow plugs get hot. I just went and got new ones as I thought maybe the ones i just installed about a month ago were shot; no change. So I guess my question is "how could I have power to the glow plugs, but they don't get hot?"

Any help would be appreciated, I'm about to take it to a mechanic...

 

have you checked the glow plug relay? id watch a few youtube vids to help me, Im having the same problem with my 90 F350 7.3 and I put a meter on the relay and its not working.

 

I just replaced the relay and I double checked it today and it appears to be working fine. It's like I have power (10-12 volts) to the glow plugs, but they are not heating up.

 

what is your symptom instead of your guess on the problem. is it a hard start cold? starts fine with the block heater plugged in?