Start engine and measure volts at battery, it should be at least 13
No, you need to check fuel pressure and the power and ground wires at the pump.
Bad coil? Bad rotor? Bad distributor cap? Bad Ballast resistor?
it could either be a bad beattery or a bad starter
You can tell by the viruses and spyware that infect your computer
That is one of many possible causes.
Typically, a bad "speed sensor" will provide an incorrect voltage input to the vehicles computer. That, in hand, would cause a problem in the speed-o-meter reading, as well as shifting problems.
Just replace it, the sensor on the top of it is usually what goes bad.
approx. $50 on each for DIY
behind the ignition switch they go bad often
No fluid, blown fuse, bad pump, plugged hose,
Usually if the resistor is bad the heater will only run on full blast.