Truck has been running fine until this morning. Was about 30 degrees and wont start. Truck will crank but not fire. Pulled 3 dtc codes. p0674, p0675, p0677. They indicate a glow plug problem. Seems weird that all 3 would go bad at once? any body have an Idea?? Seems to crank at a normal speed but wondering about batteries. Huh? Help please...