Will look into it later tonight!
I do have an update though. The Impala is not mine, its my dad'*.
Anyways, he just told me that he has to press on the accelerator a few seconds when he starts it in order to keep it from stalling.
I just tried applying 12 volts manually to the starter solenoid with the key turned to on, and wih a little accelaration by hand at the throttle linkage, the engine did'nt stall.
So actually the engine will stay on if I apply 12 volts manually to the starter.
All I have to figure out now is why the purple solenoid wire is'nt carrying 12 volts when I turn the key.
Worst comes to worst, I'll have to install a button switch inside the car and route a wire to the starter solenoid carrying 12 volts in order to start it.
Thanks Ryan, I'll definitely keep updating!