What problem can my bronco have when the temp gauage jumps around?

What is your question?

The gauage inside jumps up and down ive replaced the water pump upper radiator hose and thermostat can my problem be because i didnt do this right or is it just the temp sensors going bad. Ive also replaced the altenator new battery and terminals new ac compressor and cluch and new belt and now im having some noise like if something is hitting the fan or something i go check and nothing so it has me to believe that the fan clutch is going out but im not too sure can someone help me. This is a 1996 ford bronco with the 5.8L v8 211k on miles. Thank you for your time.

What makes this problem better or worse?

Its worse when the engine is warm

How long has your 1996 Ford Bronco had this problem?

A few weeks