Why is my car overheating

I have a 1998 Toyota camary I replaced the radiator and the thermostat I’m currently working on the radiator fan,the fan works but the relay is the issue I got a new relay but it still doesn’t turn the fan on automatically. I manually got the fans to operate by taking one of the electrical connectors to see if the car would still overheat and it does. So I total I changed my radiator my thermostat and my Fans work. what could be another problem. I’m currently bleeding my radiator so I can put some new antifreeze in it to see if it would work