04 6.0 Ex Won't Start when cold...

[emower]

Hey everyone. I've been having problems getting my 6.0 started when it's cold. Today its 50 F and I couldn't get it fired up. I know that it will start up great after its been plugged in. I wanted to figure out why its not starting on its own. I have returned back to a stock tune, verified oil pressure on the gauge, rpm on the gauges, good fuel filters, fresh oil change with castrol hypron semi-synthetic oil, good batteries. The starter cranks over great. I have only 2 DTC codes; P1000 (no worries about that) and P0603 (probably because I switched back to stock tune, but not sure). I want to check the glow plugs to see if they're working. I'm not sure what and where to check. There isn't a fuse listed in the owners manual. I've read about a control module. not sure where to go with this. Any help would be great!

Eric

[emower]

BTW I also have used a treatment of REV-X on my last oil change. So I'm kind of ruling out injector stiction.
I checked for resistence through all 4 on the driverside, under 1ohm. checked for battery voltage to the connector, got battery voltage.
I've read that maybe the glow plugs could get carboned and cause them to not heat properly. I'm going to pull one tomarrow @ work and check it out. Maybe thats all it is. I'm also going to recheck my FICM voltage now that its cold out to be sure about that. However, since it will start after being plugged in I'm leaning more towards glow plug problems.
I am assuming the engine heater is only a blanket heater and warms the block only? does it keep the fuel warmer going, too?

[emower]

I pulled the Glow plugs on the driverside. There was a little soot or carbon build-up on them. So I scotch bite cleaned them and stuck them back in. I pulled the front 2 on the passenger side. Those were clean. I couldn't get to the back to very easily today. I measured the FCIM voltage again and found it about 45vdc. Of course the engine is warm. I'm going to test it again a little later this afternoon after it cold sokes.