Code 12 = 60" switch conflicts with other switches. When truck is operating, this code is generated if the 60" switch indicates that:
The carriage is above 60" while the 24" switch indicates the carriage is below 24" or
The 60" switch indicates it is below 60" but the 150" switch indicates the carriage is above 150"

The kh, hd, hl, tm are hour meter readings. They should only show up when you hold in horn button while turning on the key switch. Double check the horn switch. Horn switch connects to carriage wiring board. Its signal, 24" signal, and wire guide switch (if equip) share a common wire to vehicle manager. This is what is called the Combo Line. The manager sees the different voltage drops across the wire and translates the drops to blow horn, 24" speed, etc.
Maybe if you solve the Code 12 problem, 82 may be also solved.

Sounds like you also installed a Lift/Lower pot. That would normally cause Code 81. New Pot has to be "Learned" through the truck program.