It's amazing how folks would rather spend BIG dollars, rather than get a professional to do the simple job of replacing the seals, as Fed Agent recommended. We had Suncoast Designer replace the seals in all 3 sections of our large drivers side window and the cost was less than $250, which is way cheaper than having all new glass installed. It also has a 5 year warranty, which the new glass does NOT have.
Bob & Betsy(FishNFanatic) - USN Aviation Ret'd '78 & LEO Ret'd '03 & "Oath Keeper Forever" '05 HR Endeavor 40PRQ, 400 Cummins-Pulling our '11 Silverado LT, Ex Cab 6.2L NHT 4x4, w/2010 Rzr or 01 V Star in back. Where the wheels are stopped today
Suggest you check out http://foggeddoublepanewindow.com/. They offer a do-it-yourself defogging kit. Used it on three windows. A bit time consuming but worked. Actually cleared the three.