Rear window defroster

HELP!!! The rear window defogger on my barn doors does not work. Any ideas? Since we had snow and ice here in Virginia Beach over the weekend, it would be a good idea for the defroster to work :) Thanks...

First check the fuse. I had the same problem and the contacts in the top of the door jamb were so badly corroded that no electricity was getting to the door. The lock would not unlock either which was my first indication something was wrong. I took some emery cloth and sanded the copper contact points on both the door and jamb and now everything is fine. Also put some vasaline on the contacts to help them from getting so corroded! The contacts are spring loaded so they wiggle around when you drive and water/salt kills the copper.
If you are locked out cause of this reason, use your hand and hit the door glass in the upper right corner while pressing the unlock button at the same time, this will move the contats a little and should give enough juice to open the lock.