glow plug testing

[u.p.cowboy]

I just had a question about doing a test on my glow plugs, I have the injectors pulled outta the engine(2000 7.3) and was just curious how to test the glow plugs while they are pulled outta the block, just put the leads from a multimeter on each end and check resitance? if so what readings should I be getting, and what lead goes to which end or does it matter?, also can somebody post a link to a good way to test the gpr?

[NoRalPh]

Here's the link for everything, shouldn't be much, if any, of a difference between out of the head and installed through the connector. Doesn't matter which way the leads are connected...

Troubleshooting GPR & GP's