CHEVROLET BLAZER INSTRUMENT CLUSTER GAUGES TACHOMETER

I Was Driving My Blazer The Other Day And Ran Just Fine But Then It Started To Make Noises And The Rpm Guages Was Jumping From 2000-5000...

I Would Like To Knpow Why I Dont Have Rpm Reading In The Rpm Gauge

2000 Blazer, 80k Miles. It Doesnt Like To Start. It Will Just Crank But Not Turn Over, Like The Battery Is Weak (jumping It Does Not...