The fan should stay on for a few seconds if you shut the car off with the AC controls on COLD (AC ON). Or it should come on when the car is off when the coolant temp is pretty high. On a stock car, I think it comes on in the 195-200plus degree range when car is off. If you have an aftermarket chip it might be diff. Also, if you do have an aftermarket chip, and a 160 degree thermostat.....the engine probably wont hit that high of a temp, so the fan wont need to come on when car is off. I dont think you have any problems. Just try the AC thing to verify that it does work when car is off.