I recently swapped my Kenwood stereo for a new one, also Kenwood. As the adapter was the same it was relatively easy to swap them over.
Everything was fine for a day. However, the unit always asks to choose a language and whether to stay in demo mode. Saved radio stations remain.
I then took the unit out again to disconnect and reconnect to see if any issues could be resolved. But now there is no power. I have checked the cables and it looks fine. I have also changed the relevant fuse (42) but still nothing. I tried my old stereo and that doesn't work either. I know nothing is wrong with the new stereo as I have had it checked in a shop.
I have been advised that changing round the red and yellow cables on the stereo may fix the resets but I still have the issue of no power.