Checking glow plugs

[idarling]

Hi
First time posting here. My 2001 2500HD diesel is giving me the OBD code for a bad glowplug. I assume that I can check the resitance for each plug to try and find the bad one. The only problem is unlike on our diesel jetta I am not sure where to check the glow plugs. Anyone got experience with this and can give me the procedure?
Thanks

[Duramaster]

Is the dtc a P0380? If so, you probably have a bad glowplug relay. The relay is actually more money (alot more) than the whole intake air heater/ glowplug relay assembly. If you look at the side of the cylinder head just above the exhaust manifolds you will see a wire attached to the glowplug with an 8mm nut. There are eight of these, four on each side of the engine. But like I said, If the dtc is a P0380, then the problem is more than likely the relay. I didn't see an exact Ohms spec for the glowplug, but they usually measure at about .9 Ohms. ;)