I third the opinion, don't waste your energy on it
But.. but.. wouldn't it give a nice warm place for mice???!!It would just jack your power bill up and not help with the truck at all.

I agree on the fuel needing treatment, anything that neutralizes algae or fungus.Stabil makes a diesel additive I believe. Never had the need for it. Biocide to keep algae from growing might be good.
Be careful with what additive you are using.Thanks for the reassurance. I figured if it was just going to stay put for winter and has adequate antifreeze it would be good. But great to hear everybody feels the same about the heater.
I changed oil, filter, and filled up w fresh diesel + Amsoil all in one for diesels, with some run through the engine for 10-12 miles.
The barn has multiple mouse traps set around the inside perimeter as well as a couple in the interior and a couple on top of the engine. Its worked well for me in the past.
I have used Howes when I used to go through the Midwest.Everyone around here uses Howes. I am not sure if it is any good or not, but that is what they all use.
Martin
Some of the concern for the fuel condition is the storage tanks at the station. If they get contaminated and pass water or junk to your truck because of no filters at the pump, or very coarse filters so that they don't have to change them. I honestly don't know if stations still have filters in the pumps anymore.Gotcha!
IME plastic tanks don't sweat like metal ones do, maybe that helps too?
if its algae, is a liquid chlorine (as used in swimming pools) an effective (and safe) additive to the diesel fuel?