These fans only run when the engine temp is high enough to engage them or when the AC in on and the pressures are high enough to activate them. They are two stage fans and they will speed up as the AC pressures rise. If they are not operating with the AC check the AC pressures and if the pressures are enough to engage the fans and they still don't work check the fan resistor located by the receiver drier. You should also check the high pressure switch located on the receiver drier. It's the one with the pigtails. You can bridge these two wires together and the fan should run if the fuse and resistor are okay.