it stopped working right as winter ended. So I never had it fixed since the season was over. Now that winter is coming soon I need to get it fixed. Is there a fuse for the rear defrost or how would I go about fixing it without spending an arm and leg. thanks.

 

Check for voltage between the two terminals. If there's voltage, the the problem is in the grid or connections. If there's no voltage, then the problem is elsewhere.
Your owners manual will have a page describing which fuses do what. Start there.
If the grid needs repair, there are kits available at the autoparts stores.
Search the web for information on how to troubleshoot and repair the defroster grid. There are lots of sources with lots of good information.