Consider polymerization, not now but for the future:
http://www.frybrid.com/svo.htm


No lite can mean no glow.
Research glow system & troubleshoot.

You may have fat that settled to the bottom of the tank. Pull supply & return off hard lines, & blow tank w/ Low pressure air. I've heard of using a rag wrapped around an air nozzel and jam it in the tank.

Move to heated garage if possible, plug in, or leave hairdryer running under hood for a few hours.

Feed supply & return lines w/ jar of D2
Loosen hard lines at injectors, crank w/ skinny pedal on the floor till diesel flows out, tighten.

Crank 15 sec, wait a few minutes- don't cook your starter.