Check locations 4 and 32 in the power junction box under the hood. 4 is the backlite relay and 32 is the heated backlite. I think backlite means back window. I assume you have a 10?

Also, these are called out in the manual around pp 326-328 or so (first printing anyways).

 

Thank for the info John, that was just what I needed to know.

Unfortunately when I checked with the local glass shop and they want $289 to replace the back glass so this project quickly jumped to close to $400, times 2 trucks, and took the wind out of my sails.