Rear Defrost Broken - Help Please

My rear defrost stopped working a couple of weeks ago and I just has a chance to have a look at it now. The first thing I checked was to make sure there was power at the window and I found that the passengar side connection has power but the driver side does not. I checked the fuses but the only thing I found in the manual was a rear defrost relay, not fuse. How is it possible that only one side of the the defrost has power but the other doesn't. The van is a 2000 SEL and any help would be greatly appreciated.

My rear defrost stopped working a couple of weeks ago and I just has a chance to have a look at it now. The first thing I checked was to make sure there was power at the window and I found that the passengar side connection has power but the driver side does not. I checked the fuses but the only thing I found in the manual was a rear defrost relay, not fuse. How is it possible that only one side of the the defrost has power but the other doesn't. The van is a 2000 SEL and any help would be greatly appreciated.
The rear defroster is a resistive wire (multiple wires) that become hot when a positive current is applied on one side and negative on the other side, so I think it is normal that you have positive only on one side. However you have to be sure that the other side is also connected to the ground. There should be no resistance between the negative side ( of the the grid) and the body of the van. (ground)