I have a 100% charge on my battery, but I’m having trouble getting it to start. However, I have also had trouble with the battery due to corrosion
So did you FIX the corrosion? How do you know the battery is 100% charged? Is the car cranking? Or cranking but not starting?
I would guess that this is the original battery and I doubt if it really has 100 %. It may show 12 volts but still not be able to start vehicle. If the vehicle is running depending on where you are Autozone may check the battery for you . And as to Mustangs question if you have not cleaned the connections do so now.