Rear defrost junction block?

[327chevy]

Is there a junction block for the wiring that feeds the rear window defrost? My heated mirrors quit working as well so I read about the junction block under the front drivers side kick panel and sure enough the wire was burnt off so I figured the whole heating circuit was fixed.As it was the repair was done at a time of year when the need for heating the mirrors or rear window wasn't needed but now that winter is just around the corner and I have actually used the mirror heaters a couple times already and noticed that the rear window isn't defogging.So before I start tearing panels off can someone tell me if there is actually another junction block I should be looking for or perhaps a weak spot.

[aleekat]

I would test first power going to the grid. If power there, then the grid itself. Simple voltmeter/circuit tester will work.