camera image pulsates after relay

I've searched to no avail and looking for help... I just installed Navtool video interface and Boyo backup camera in my '05 BMW X5 with factory Nav. Everything works fine with ignition on/engine off (camera kicks on when I shift into reverse, image stays on screen, etc.) but when I start the engine and shift into reverse the camera image only stays on for a second or two then switches back and forth to the nav screen... I can't seem to figure out what is different with the ignition on vs. turning the engine on... I suspect the relay wiring which I installed as follows since I have eliminated everything else... 85= ground 86= reverse light trigger wire 87= Navtool video module trigger (blue wire) 87a= not used 30= switched power Any help much appreciated... Rob

How quickly does it switch back and forth? You will need to start testing wires with a volt meter. When in reverse Pin 87 should read constant 12vdc. Start here and make sure you are telling the system to display the rear camera. If this voltage is pulsating then you need to find a constant source.Kevin Pierson

about every second it switched from camera picture back to factory nav screen... kept bouncing back and forth... I took out the relay, tested all the wires and rewired back in a new relay and all is working fine... Just for kicks I tried the old relay and all worked fine with it as well... I am now thinking I must have missed a wire along the way or some other user error... Thanks for the assist... Rob