2003 6.0 Engine Miss

[wrencher73]

2003 F-250 6.0 engine misses at all rpm hot or cold and clatters when rpm is raised above idle. I unplugged injector harness connections 1 at a time of coarse and #6 was a dead hole. Because these injectors seem to be the most cause of engine miss I replaced that injector. Well guess what #6 is still a dead hole. So to check for broken injector harness wire do I check voltage at injector plug. There are 4 wires at each injector plug, what should voltage be and at which wire. Maybe a head gasket. Any thoughts.

Thanks For The Advice
Wrencher73