Juice not getting to glow plug relay?
 

Back again, gentlemen...with more information and less solutions! *Laugh*

So the (original) GPR works fine...solenoid kicks in and current crosses the lugs like a champ. However, this was discovered "manually" by connecting it directly to the battery, so...

...the question: No juice is getting to the GPR from the smaller wires that are supposed to actuate it. Obviously it could be any number of things, but is there something common anyone knows about? Any directions to follow would be appreciated.

Other details (about the truck issues in general):

Aside from the GPR not getting any juice when the key is in GP position - it turns out that 7 of the 8 GP's were bad, so they're being replaced. Also, one of the GP terminals on the electrical plug that goes into the driver's side valve cover (gasket) was burned out, and therefore required a new $91 valve cover gasket.

In addition, the mechanic plugged in the OBD-II and the truck blew a number of codes. He cleared them, and I don't recall if they showed up again.

Lastly, an "advertisement" - If you get a chance to pick up one of those "lifetime guaranteed" GPR's at O'Reilly's or AutoZone - just don't. The first one I bought failed, so I simply returned it. Mind you, I should have checked the original before bothering with a new one, but for $50, no big deal, right? Yeah, except that a lifetime guarantee doesn't do you any good if you're dead in the water in the middle of nowhere.

Thanks in advance...

- AJWright64

Sorry, forgot to mention it's a 1999 Ford F-350 SuperDuty crew cab, long box with the 7.3 PowerStroke TurboDiesel

For anyone intetested: As it turns out, the problem was that the harness was unplugged from its receptacle on the valve cover gasket, so the circuit wasn't completed or something along those lines.

So, $700 later, I have a new block heater plug, a new valve cover gasket, all new glow plugs, a new plug for the driver's side harness, and everything starts and runs well. It had shown a number of codes with the OBD-II (handheld) during the process, so I'm going to get those checked again soon.