1990 k1500 v6 base model manual tranny my speedometer and heater fan quit working. they seem related as they quit together and occasionally will kick back on together. unknown if related is the 4low still works, but the 4high doesn't, and the indicator light doesn't work. everything else is working like always. horn and turn signal disengage and high beam switch i left out when changing the ignition, cab light is always on so i have to pop the bulb, but those are old issues i just live with. oh and the battery gauge always reads high red but it checked out right with a volt meter so that seems the gauge is just bad. i've checked the heater control fuse, so i think it may be a bad ground somewhere as they just quit randomly while driving. does anyone have any idea where that ground would be located? or any other ideas what could be wrong? it has had a few issues since it is a 90 in ohio but i love my truck too much to see it go to junk, had is since high school (ten years now). thanks for any help.