Just get the FCM to run like it should, if problems persist after that, you need an ECU. There are places to have the ECU fixed, which is good, because a new one is around $2400. Josh at the MSS can re-map a used one to your car, if it comes to that, I'd expect the used ECU and Josh's programming to total around $500. But let's get the FCM to act right first, if it does not turn the fan on it's own with the PWM wire to the ECU disconnected, the FCM is bad or you have no power to either the Red cable or the little IGN lead. Simple as that.