Here is an update on some of the things that have been done...
I managed to get the turn signals working. The turn signal switch itself was an aftermarket Signal Stat model 900 that was in actually very good condition. This is a 7 wire unit that is designed to use the same element for the turn signal as the brake light. These work well, are reliable and are easy to wire. The one thing to remember is that these units need a 3 prong flasher for them to operate correctly. The third prong on the flasher is designed for the indicator lights that are built into the Signal Stat. Usually, this the blue wire.
When I wire these aftermarket switches up, I generally like to use the standard GM column plugs. These can be found at Jegs relatively inexpensively. I like to do this for several reasons, first, since all of the wires in the harness are GM colors, it's easy to get a diagram for diagnosis later down the road. Secondly, if the owner ever wanted to put a late model tilt column in, the wiring would just plug in.
The Signal Stat only uses one flasher for both the turn signals and the hazards. Most aftermarket harnesses have separate flashers for each, so on the harness side of the plug, there are going to be extra wires. I just wire them in like there are for a later model column and leave them at that.
It's always a good feeling when stuff works...
Another accomplishment was the horn. This vintage GM truck has an unique upper bearing that incorporated the horn circuit into it. The bearing is mounted in rubber and has a wire connect to it that rus through the column and exits about 1/2 way down. On the top of the bearing, there is a spring loaded contact in the steering wheel that rides on the bearing lip. When the horn button is pressed, a ground connection is made from the steering shaft which then closes the circuit of the horn relay.
And here is a video...
Also, we also cannot forget about the dome light.
