Why is my car still overheating? Replaced the.

Why is my car still overheating? Replaced the thermostat, replaced a cracked hose that was leaking all my water out of the radiator. However, my radiator fan has stopped working, replaced the motor on the fan, replaced the relay switch, my fuses seem to be fine, but still does not kick on by itself. I had my stepdad run a wire from the fan directly to my battery and I manually turn the fan on and off. I also broke the overflow cap off, The problem seems more serious then all of that. I don't understand why it keeps getting hot and my heater blows out cold air as well.