Your blinkers and power windows are both switched through the ignition switch. Your problem sounds a bit different than mine, I think I sent you in the wrong direction with the fusible links (sorry!) Have you taken the steering column apart and/or poked around the connections at the bottom of the column?

 

Just saw this thread and thought I'd add my 0.02 ..

My connector at the bottom of the steering column came loose and I had most of your symptoms, not all but most...Mine started when I hooked up my shutdown timer.

The connectors don't stay in good because the wires seem to be about 1/4" too short. If you've been under the dash poking around, running new wires, etc. I'd suspect the connectors.

 

thanks, I'll give 'er a shot and try and tighten it up! The fuses seem fine and I can't seem to find a ground. I will run a new cab-frame ground and see about that connection. HOwever, the shutdown started BEFORE I was under the dash, but this thing bounces around a lot, and there is evidence the PO was under the dash alot. Hopefully it's something like this just coming loose.

 

a long overdue update on this problem for anyone finding this in a search.

The problem was the ignition switch. The ignition switch was bad for a long time and the PO installed a push button starter to get by. The failed ignition switch was causing the fusible links to blow. I replaced all fusible links with MAXI fuses and 1 of the 2 major fuses that go through the switch was popping. Replaced the switch and my problems went away, plus I had a normal key to start the truck again.