well, if your coolant guage wont work, then i would check to make sure it's connected to the sensor in the head (possibly block, but i dont remember). my older truck (a 73) was just not hooked up to the sensor for whatever reason and the guage started working again. i have no idea if the newer models use the same type of setup to get the temperature reading or not. i should know though, since i have a 95 k1500 myself. it could be that your wiring is shot to the guage in the dash, since many of my idiot lights no longer work, such as the "shift up" light (it's a stick), low gas light, and who knows what other stuff that was broke before i bought it. i have heard that these trucks are famous for their wiring problems, and of course sagging doors