The OP talks about voltage on the wire to the reversing valve changing
when the unit is blowing cold air vs warm. I assume he is checking from
Red to Orange, as he says it is 24+ when the unit is heating an 0 when
it is blowing cold air. This would iindicate that the valve is getting
power and is most likely OK--luckily, since replacing a reversing valve
is no small job. No matter what is powering the valve when it is not
supposed to be,it is going to be minor compared to replacing the valve.
Larry