I just installed a coolant filter in my 92 7.3. Had the wrong fitting so ended up waiting about a week and didn't run the truck. Finished up this afternoon and went to take the truck for a drive and make sure the heat works. Turned the key to the wait to start position. No glow plugs, no lights, nothing. Turned it all the way over and nothing.

Batteries should have plenty of life left and the truck has no problems starting typically, but its about 20 degrees fahrenheit here in northern Indiana today and its been cold for the last few days. I suppose a dead battery is a possibility, but I would think I'd at least see something when cranking. Its almost as if its not connected, but posts look fine.

Any ideas? As always, I appreciate the help.

 

Also, for the record, tried jumping with no success.

 

Do you hear a click from the relay?

If not, you can do it manually:
1. Put the truck in park/neutral, with the brake on
2. Pop the hood.
3. Find the relay on the passenger fender well. It has 1 small terminal on top, and 2 larger ones below it.
4. Use a screwdriver to bridge between the small terminal(you'll need to pull the wire off of it), and the large terminal which has all the wires coming out of it.

If it cranks, look at the ignition switch, clutch switch(if manual).
If not, look at the starter and wiring.