2010 Jayco 31FS Battery Issue

Here is my problem. The emergency start does not work and the house battery is not charging when the truck is running. I found the emergency relay under the hood . With my meter I found house battery voltage on one side and truck battery voltage on the other side. With the emergency button pushed I have house voltage on both of the small terminals of the relay. With the truck running I truck battery voltage on both of the small terminals.I shut the truck off and disconnected the red wire off the small terminal and found house voltage with the emergency button pushed, reconnected and disconnected the white wire off of the small terminal and had no voltage. I left rang the white wire out for ground. It was open, no ground found.
I then made a jumper and went from the small termianl where the white wire was and ground. The relay closed and the house battery was connected to the truck battery. I then started the truck and used the jumper to ground and the house battery was being charged from truck.
Sorry for the long story. I dont understand why I lost the ground? Everything was fine when the rv was put away in the late fall.

Thoughts Please.