Lights wont go off and O/D light flashing

[BULLDOG13]

Hi Guys please help. I have a 2001 7.3 diesal f350 It has about 115.000 miles never any issues was plowing snow last night with windows open all the light went out about 3 hours into it then little while longer they all went on and wont go off unless I dissconecte batteries cable also the o/d light is flashing. When I put it into reverse the truck sputters little and the radio goes crazy. I know this sounds crazy but its is what it is lol, the tranny seems fine shiffting ok no noise or issues.PLEASE SEND IDEAS thanks guys could it be some electrical short

[NoRalPh]

Look above the fusebox, at the GEM module that controls all that, for evidence of water leaking on it from the lower corner of the windshield above.

A common issue...