So I have 07 T&C 3.8L. it was parked for a few weeks battery went dead. I don't drive it much as it's soul purpose is to transport resuce great danes. Bought a new battery. Went to start it. No crank. I took jumper wire to starter relay and cranked over. Determined the starter was good as well as a wiring from fuse box to starter. No spark and no fuel pump. I rented a snapon edge plugged in and It read Run/Start Hardware Input Failure. Will not read ecm. Picks up every other on board computer i believe. Went and picked up ecm from local salvage yard. Installed it. Still the same. No crank/no start, no fuel pump and I get Run/Start Hardware Input Failure. I guess my question is, I located a fcm on the front of fuse box. What is it's purpose or functions and any advice to get this van back up and running would be greatly appreciated im lost at this point. Thank you in advance.