Temp gauge
 

Any ideas on why temp gauge is jumping from 150-250 rapidly and bounce around? Will sometimes jump from 100 to 250 very quick and will never show actual temp. Jeep is cold and just started . Also electric fan is not kicking on. Already changed temp sensor and did not work. I checked if electric fan works and it does. So it’s clearly not getting power.

Forgot to mention just changed radiator for a faulty one with a hole in it. Temp gauge was broke before I changed radiator though. I burped the system for a good while and no change.

Follow the wire from the temp gauge sending unit on the back of the head. It could have a bare spot or be pinched.