Instrument gremlins.

It's easy to try the fuse, but no gurantee. Radio Shack or the chain auto stores. Buss Fuses or Littlefuse brands are the best.
I'm holding onto hope that it is a fuse. Yesterday it was 20 outside with gusts up to 40, that fuse box ain't going anywhere.
I first thought I screwed something up with the grounds when I did the H$ headlights off relays. But having all 4 blinkers not working is hopeful.