I replaced the fans but they still don't run.. is it a bad relay switch?

 

When mine quit workin I just wired mine up to a fuse that comes on with the switch

 

First of all does the car get hot or something at stops? The fans will only turn on when they need to. Yes the fan has a fuse and relay that will need to be checked. After you confirm there good I would use an obd2 scanner to make sure the coolant temp sensor is working properly, then use the scanner to see if the computer is commanding the fans to turn on.