Left my headlights on for two days. Cranking and all lights come on in dash. Took heavy duty battery out (only a year old) had it charged. Still won’t start. It’s not the fuel pump as that’s been replaced. Battery at the auto parts store was reading 12.5 volts and 100% charged.

Any tricks I should be trying? Thanks!

 

Any codes? Also does the red light on the center console continuously blink (or blink very fast, can't remember) when you insert the key and turn it to the ignition position, or does it blink/stay solid for a couple of seconds then turn off.

After checking those two things: Does the car crank over at normal speed or does it barely want to crank at all? If you really ran the battery to a very low voltage, even if you charge it back up, it could still be damaged and have very little cranking amps, or have a bad cell. I'd consider hooking a second car up with jumper cables or using a jump pack to rule it out.

 

No codes, no flashing lights, it all looks normal on the dash. Tried jumping, put a brand new battery in and nothing’s changed. Cranks fine but won’t start. Help! 😂

 

Make sure your inertia switch hasn't tripped out for some reason.
That shuts off fuel supply.
RHS lower A pillar