5.3 swap check engine light on

[Ken Davis]

This morning I started my 72 that I recently installed a 5.3. The truck only has the cab installed on chassis. The motor has been running great. This morning it did not want to run so I added some gas. Now the check engine light is on it seems to be running fine. So I plugged my scanner in which I have never done to this truck. The scanner will not come on. The plug on the truck the pink wire is hot. I have disconnected my battery the light is still on. Does anyone have any ideas what to check to make my scanner work. I know the scanner works I checked it on another vehicle.