temperature

does anyone know what would cause my heater to turn on and off without touching anything?? it stopped working one day but lately came back to life but will turn off and on at random times. my temperature gauge will do the same thing. it bounces all over the place and then goes away or will read fine. is it something to do with grounding them or a bad connection??

sounds like you have a short somewhere, look around to see if you have any bare wires tounching anything