My blinkers stopped working last week... flashers work, brakes works, lights work though.
That means that the wires are good, the housings and sockets and grounds are good, and the bulbs are good.
When you do all of your testing, make sure that the key is on, of course. You probably did for some, but it’s really easy to forget during some tests, so I mentioned it.
Did you try swapping the four-way flasher unit with the turn signal flasher unit? They are two separate systems at that point, where the hazard flashers are powered all the time, but the turn signal flasher is only powered with the key on. But since the two flasher units are Using identical, connector orientation, they can easily be swapped for testing.
I've pulled the steering wheel off to inspect the wires and all looks good but I don't know what should be getting power.
With the key off, nothing except the horn.
Looks like you have a pre-74? Up to possibly an early 74. Two horn contact means no horn relay.
I have power to the horn terminal, should I have power to the blue or green wires on the left side?
Don’t have the colors memorized, but if the hazard flasher switch and the key are off, no. Only the horn would have power at that point.
Power comes in on one horn wire, and when you press the horn button it goes out on the other directly to the horn.