please help 01 dodge diesel has trouble starting when cold
 

I have been reviewing the post in this forum and not finding answer to why my truck is hard starting when cold. I talk to 1 person who said that it might be fuel pressure but that's not a problem I have 20 psi and the pump engages immediately when starting. I have even cycled the lift pump several times to verify that I have fuel pressure, but it still doesn't want to fire right up. I always leave it plugged in when it is this cold.
My voltmeter does drop severely down to about 11 volts when first starting up though.
Does this mean my grid heater has gone south?
Any help is very much appreciated.
:s: