Why would the windshield wipers blinkers and brake lights all go out on a 1991 Chevy Blazer?
Start with the easiest possible solution first; it is most definitely a fuse so look in your owner's manual or possibly even on the fuse box to see which fuse controls those things, take it out and it's probably shot.
First, your headlight switch must be in the "ON" position, even if your lights stay on all the time. If your switch is "ON" you simply pull the controller to engage your windshield washers. The Headlight washers operate when the windshield washers operate. Get someone to watch them as you wash your windshield or you can shine your lights onto a wall and see the shadows as they operate.
I use to put cardboard on the glass under the wipers, leaving the wipers laying on the cardboard to hold it in place. Unless it is raining, the cardboard does not get soggy, and does not freeze to the windshield and the wipers do not freeze to the cardboard. I lived in PA for 38 years so I have dealt with ice and snow. Then I wised up and moved here to Arizona. 70 degrees…