I have a f90bt, i have had it and the pioneer backup camera for a while now, it all of a sudden has stopped working when i put my truck in reverse. it works if i pick the camera manually or if i set it to ground not battery like it has always been set on. I have checked all connections. Please help

put a volt meter on the reverse-in wire, make sure it goes to +12vDC when in reverse. the resistor fuse might have had a meltdown.

yea i agree with the blown fuse, if you can select the camera and it works then the problem is not with the camera but with the unit detecting the reverse signal, while using the meter check both sides of the inline fuse (little black thing on the wire) if both sides have voltage then the wire might have been cut or disconnected fight before the head unit, if there is voltage only before the fuse and not after the fuse, then of course its the fuse. if there is not voltage on either side of the fuse there wire probably came disconnected at the source (where it was tapped into the factory reverse wire)