Joirney

Sorry I'll elaborate. The rear camera has not been working for 4 months. Last week before a road trip and after a oil change I cleaned the engine. After that the camera worked and the button did not. After the road trip and lots of KM on gravel roads I rinsed the  engine off on the low wash setting and the button worked and the camera didn't. The wiring harness on the hatch is not in great shape and I have fixed several cracked wires in it. I just can't figure out how the two switched (button/camera) and the only link is the wash on the engine. How are the two connected and why or what would be a reason why only one can work at a time. 

2013  dodge Jouney RT. the rear back up cam wasn't working then the I washed the engine and the rear camera worked again but the rear hatch button stopped working. Washed the engine again the back up camera stopped working and the button works again. Is there a switch/ line has anyone else experienced this.