Hello, I understand that you do not wish to continue... that is no problem on my end. However it is apparent that there is either no power to the unit under the house, or a fuse on the printed circuit card in that unit has blown, or there is a bad 24 volt transformer in the outside unit.
If you wanted to check that you would go back under the house and remove the only two service panels on the accessible side of the unit. One of those will have a blower behind it, and there will be a printed circuit card mounted on the blower.
The wires that come from the thermostat will all end up there... check between the R terminal (red wire in most cases) and the C terminal...if you get no voltage read the transformer is bad or your homes main breaker panel that has a breaker in it marked AC or Furnace has tripped.
Look that over if you like, we can go from there.
Here are some pictures of typical printed circuit boards.
The unit under the house probably looks something like this.
service panel for the blower compartment is at one of the areas marked with a red square.
Stay in touch if you wish, we can go from there.
Please hold your rating if you choose to hang in with me until we get the problem solved.