Anybody know which pin to check injector voltage on a 7.3?

 

You can't with a standard ohm/volt meter because it's an AC type of voltage.

GP - I - G - I - GP

GP = glow plug
G = injectors ground
I = injector

It would be helpful to describe the problem why you want to do as stated.

 

It's NOT AC voltage. Even if it were, a standard multimeter reads AC voltage. It's 100VDC. You can't read it because it's energized for such a short time. You need a noid light capable of reading high DC voltage. Or an analog meter with a needle that responds quickly to very short bursts.