1995 c4 corvette. Cooling fans only come on when the ac is running

I would first check the coolant temperature sensor.

Radiator hoses that been replaced the thermostat has been replaced and the coolant temperature sensor has been replaced

Locate the hot wire that powers the fan , check the relay .If all else fails . Locate a wire under the dash that is hot when the ignition is on and run a wire to that point . So the fan runs when the key is on.

The A/C turns on the high speed fans and or all the fans if you have two fans. It is on a separate line. So first make sure the fans are good. Check all the circuit breakers and fuses going to the fans. Check the computer manual and see if you need to mate the new sensor to the computer. The fan thermostat may be bad also . Like mentioned above, hot wire past the thermocouple and see if the fans come on. If they do, change the thermocouple. If the fans do not come on by going around the thermocouple, it is the fan motor low motor..