this is a crown im assuming
GE labels those just as TB1-6
crown adds the 11

anywho

tb-2 is the brake switch and start of accel switch (if equipped) battery volts with the brake released and the accel depressed (the brake switch is normally closed)

tb-3 is the seat switch or operator presence switch (for the stand up) battery volts

tb-4 is battery volts from the key switch

what problem/ code do you have?

every tb connection reads battery volts except tb-1 for the pot