Been off the forums a while due to family health issues, but hopefully back for a bit.

Got an 04.5 2500 that has sat a few years. When I got it here a few years ago, it was running, but the transmission was shot due to a leak in the torque converter cooler.
Went to crank it today, and it will roll over, but not fire off. I have no gauges while rolling it over, but they all work when you hold the odometer reset (they all do a full sweep), batteries were good, as they are the ones from my 06. No codes shown on message center/odometer. Can NOT get my scanner to connect.
Put power to the lift pump, can get fuel to the filter, so it is good.
Didn’t see any bad wires to IP, cam or crank sensors. Tried unplugging the fan clutch with no change.

what am I overlooking?

Thank you