What causes a 2000 Chevy Blazer not to start?

The fuel pump is priming, but nothing is cranking. I have a engine with nothing making any noises. Turn key and just no noise from starter, or anything outside of a few electrical items. Now wondering about ECU going out.

The ecm won't prevent the starter from turning or engaging try jumping the starter with the key on. Little stud to big stud, if it turns over then check ur ignition switch.

Btw if it turns over with the key on then it should start. If it doesn't turn over then check voltage at the big stud. Its marked B

neutral safety switch ...

I have a 2000 chev blazer 6 cyl never had a problem starting before now ,ran great gas level was between 1/4 and e ,it was real cold one night and the next day it would not start. I put 3 gal gas and some heet in it and it still won't start.fuel pump is working but back firer and tries to start. 3 days later still don't start. any suggestion ?

Our starter won't strt if it is really cold outside unless my hubby takes a hair dryer and warms it up! seriously she is stubborn!

News fiel pump Not gering Gas to start

News fuel pump still Not Rettung Gas to start

If solenoid bad will sit in positiin an spin.....but will not engage flywheel.....so essintially starter might test goid

Could someone help me I got 2000 Chevy blazer 2 door No crank nor start Alternators good few pump is good Starter is good I replace Wires plugs and much more still don't start