OK, I am now convinced it must be the switch.
If I jump B+ and B- to each pair of contacts, I can make each motor function, and reversing the leads, reverses the motor, Therefore the wiring from the switch to the seat must be OK.

I have 12volt (B+) at the red/ white wire. If I check the terminals on the back of the switch with the 6 wire plug connected, and the 5 wire plug disconected, As I operate the recline, and the rear rise and fall, I get 12volt (B+) at each of the 4 terminals--I never see a B-.
I have checked continuity all along the ground brass strip inside the switch and can find no problems or breaks.
I have opened,and cleaned the switch about 6 times. I have put it together dry, and with dielectric grease everywhere, and with dielectric grease only on the top balls to keep them from falling off the springs. I have not returned the brass wings to the same slots, and yet every time I reassemble it, I have the same function--front half OK; rear half--dead.
Can it be anything else BUT the switch?