Hey, thanks for all the good info. I did not know about the speedo indicator.

Well, I dove back under the dash, and found that there were 7 wires leaving the steering column control, but only 6 exiting the messy, sticky mass of electrical tape that the PO favored. What's wrong in this picture? So I removed the tape, and sure enough PO had taped the yellow and blue together and used the 2-prong flasher. Which is maybe what he had on hand?

Twelve bucks later I was good to go with a new flasher and socket. "X" to the fused power, "L" to the yellow load, and "P" to the blue pilot hazard indicator. Everything works great.

BTW, NAPA did not have a flasher socket, but a three prong headlight socket works fine.

Thanks again guys.

Harry