Update: I pulled the pan, the 4th gear switch was n/c single pole and opened under pressure, the 4-3 switch n/o dual pole. Bingo! I used a n/o dual pole in the 4th gear lock up port. Problem fixed and it works.

1946 Chevy 1/2-Ton
"Elvis"
In the Stovebolt Gallery
The Build pix on Photobucket