OK, the truck isn't misbehaving right now (of course) but I put a meter on it to get a baseline anyway...

Main switch ON, DeadMan Switch ON:
1-2 : 20v
1-3 : 20v
4-5 : 24v
4-6 : 24v

Main Switch ON, DMS ON, Throttle FWD:
1-2 : 20v
1-3 : 20v
4-5 : 1.5v
4-6 : 24v

Main Switch ON, DMS ON, Throttle REV:
1-2 : 20v
1-3 : 20v
4-5 : 24v
4-6 : 1.5v

So yeah, clearly the bottom row is the directional switches.

For what its worth, I also checked for continuity between the back plane and each of the six terminals. With common to the back plane, and the main switch OFF, I got continuity to all six screws.

With tha main switch ON, I got continuity to terminals 1,2,3,5,6, but not 4.

If I switched to put positive on the back plane and common to the terminals, I got the exact opposite reading. So is there some diode action going on there?

Next time the truck dies out on me I'll check the terminals again and let you guys know what I find. In the mean time, do all these readings sound right?

THANKS AGAIN!