My brother in law just purchased a 2004 crossfire. He brought it to my house and it wouldn't crank. The lights come on and after a bit the cooling fan revs up ( is this normal?) He pulled the rcb and we resoldered connections ( they still looked good but did it anyway) The ecm will not communicate with any of my scan tools ( also have Alex Peppers scan tool) Where can we start trouble shooting? I do not believe the ecm is working but I don't know an indication to look for. Any suggestions would be appreciated as I would love to take this car for a spin. Thanks