Any suggestions on how to fix the radiator fans on my 99 Grand Am. Both fans don't even kick on after I turn on the ac like they did before. I replace the coolant tank all hose just replace the coolant temps sensor and all the fuses are good. I ran a power source to the fans and they worked fine.
Have you checked the fan relay? It should be in the fusebox/power center under the hood. You can check the relay by swapping it with another identical relay out of the fuse box. You can also try checking it by having an assistant start the car and cycle the a/c on and off. With your finger on the relay you may be able to feel the tick as the contacts close. It may also be a wiring issue between the ECM (engine control module) and the relay or between the relay and the fan.