1993 Explorer, Rear defroster doesn't work

Get a test light disconnect the connector from the rear defroster and look for power-

There is no DC voltage to the rear defroster when the switch is pressed. I tried this from both window connections to ground and across each other. The resistance accross the defroster is 1 ohm. However, as I mentioned, you can hear the relay clicking in inside the switch. And yes, I did check my meter against a good power source

Update
I took the switch apart and it is the attached photo.
I can energize the relay and see it operate. However, there is no voltage to the relay contacts. there is also no power at the rear defroster when enegerized.

There is no mention of a fuse in any of the auto store books I have nor is there a fuse mentioned in the owners manual. I have checked all the fuses I could find.

Does anyone know which fuse it is?

Could this be an issue with the ignition switch?

If you can hear the relay cliick-now the question is it coming out of the relay to the rear defroster grid.

Do you have power to the relay connector when key is On and switch energized.

You need an EWD to know what's in between the relay and the switch and therfore.

I ordered a wiring diagram for the car and found that, as I suspected, there was another fuse involved. The control has a seperate power source from the actual circuit that heats the window. The power for the actual heater comes from the fuse box under the hood. I had checked all the fuses and all were good. However, aparently, in an pervious time when I checked the fuses there, I put the 40a fuse for the rear window defroster in the power assist shift slot by mistake (which calls for a 20a fuse). I don't have power assist shifting, so I pulled the 40a fuse and put it in the "HTD BLITE" slot. It now works.