Two places to look, we had the same problem on our 29M. Under the coach at the very rear was a big bundle of wires that was hanging loose and bouncing around, after securing the wires no more problems. Remove the large cover over the dash, look for a small silver box with three camera leads and trigger wires from turn signals and reverse, it was dangling also, secured it with zip ties. You can trace from the box to your radio and look at connections. Good luck!
Dave & Myra
One day your life will flash before your eyes,
make sure it's worth watching!