Rear defrost doesn't work.

Rear defrost on my 98 Legacy GT limited stopped working almost a year ago. It's been pissing me off for a while now.

It's one of the ones with a momentary button and a timer. Why it needs all that complicated crap is beyond me.

But anyway, it won't work. I changed the button with one I know works. And nothing. I don't hear the relay under the dash clicking, the light on the button doesn't light up.

If I apply power directly to the rear defrost it actually works. So it's some of the stupid electronics in the middle.

What do I need to do to fix it?

Oh, and before someone asks. No fuses are blown.