Having a shed clear out and came across this set-up I had on my old 94 Bighorn.
When the Bighorn died I saved this for another project, but that didn't happen.
It was wired to a temp switch in the hose and another over-ride switch on the dash, those parts have 'disappeared'.
Anyone interested? Open to offers as otherwise it'll be dismantled and ditched at the tip - I'm under orders!