I have a 2007 dodge ram 1500 with the 5.7 hemi. 4x4 quad cab. I bought it with a bad motor. So I took the motor from an 04 dodge ram 1500 5.7 and put it into the 07. I used the existing 07 wiring harness and even used the 07 starter and even switch the valve covers to the updated coils. Everything wired up and bolted up fine.. here is my issue. When I turn the key forward I noticed that the PRND21 is not showing on the dash. Secondly, the abs light and brake light will illuminate and go out and come back on. Turn the key and nothing. No crank, no start. So I plugged a snap on scanner into the obdport and pretty much said nothing is communicating. Windows work. Radio works. Heater controls work. Everything works as it should. Just at a loss. Is it as simple as the computer needing to be flashed or something more complicated. right now I am just at a loss. Please help.

 

I would start by checking you power and grounds. A connector maybe unplugged either in the engine compartment or under the dash.

 

I know One of the grounds broke. The one behind the block, goes from head to head then I am assuming to the body.. do you happen to know of the locations of the grounds?