I have a 2008 T & C and last week the screen started going black whenever I put the van in reverse. I checked the fuses I couldn't see anything blown but I don't really know which fuse goes to the camera or screen.

 

I have replaced the backup camera and M31 fuse keeps blowing causing the reverse light not to work. Any thought?

 

Sounds like you may have a short in the circuitry. If you have access to a multimeter you should check continuity between the fuse and camera first and then if the connection at the camera has continuity with earth, the latter meaning you have a short to earth. This will draw too many amps causing the blown fuse. If so locate the part of the wire going to earth and repair or replace. Another way to confirm is to attach a longer seperate piece of wire from the fuse straight to the camera to eliminate the existing harness. If it now works without blowing the fuse you know the harness is the problem.
Good luck, Dan