Just got this truck and having problems on cold starts below 55 degrees.
I have changed the gpr and still have same problem. I have checked the voltage at both studs with key on voltage is below 10 on glow plug stud and main stud
Not sure what would be causing the voltage drop as soon as I turn he key off the main threaded stud jumps back up to 12.75 turn key on and both big studs are very low
Any help or suggestions would be great

 

A large voltage drop is usually caused by increased resistance in a component. If voltage is good when the glow plug lead is disconnected from the GP. I would say you have a bad GP in the system. I am not sure what the ohms are on your glow plugs, but you could try isolating each plug and checking resistance for each one.

 

I will check to see what the voltage is when it's disconnected also check the ohms I did notice the relay does click several times with the new one and the old one is this normal

 

sorry don't know that answer, a relay clicking in and out is usually not normal, unless like on a 2nd gen dodge where the heater grids time cycle by the PCM.

 

Gpr seems to be fine just tried starting and took 45 mins till she cranked I had more white smoke than ever once the trucks warm she runs like a champ

 

how are the batteries? Definitely don't want to wash the cylinders down with fuel to much! I would avoid extended key cycle cranking.
I would lean toward whatever component is supplying power to the glow plugs. To have a whole set of glow plugs bad would be strange. Sorry i am not much help maybe some International guys can help more.

 

The ohms should be around 1.2 for most. Also check wires I found a wire going to one of my glow plugs was rubbed raw causing me to have same issue.