Is this my electrical short ?

speedo... someday when you have time, you have to unhook the cable, pull the center guts of the cable out ... clean it with something like WD40, then dry it off lube it with thin coat of vaseline. (vaseline wont freeze in cold like other stuff)

dash glitchies... probably grounding. especially make sure you have a ground strap from the head to firewall/wiper motor bolt. that one often gets forgotten.