How do I cable directly from AC to Thermostat bypassing the untested corroded telecommunication?

Should I obtain my nouns ducts cleaned?
Answers:    "from AC" is not much of a description. Is this a package unit? Normally your thermostat wires run to the air handler or the furnace. Then the condenser is wired from there.

Not sure what wires you are replacing.

With single two wires you are either going only to the condenser or it is a bag unit with no steam or you have a separate thermostat for heat.
How can u speak about how much gas...
If your conversation about a/c thermostat wire , which I judge you are, The wire is what is called low voltage lead (24 volts). Simply cut out the corroded section and splice in trial wire, which you can purchased at any hardware store, it's the same as doorbell telecommunication.
How do you fix concrete parging to be...
You have two choices. You can run new wires over principal in Attic and down wall., or can ohm the existing wires to see if you have two apposite ones and use which every two are good. However be care full if they are corroded as you utter they may be touching together and give you a false reading while ohming them.Hope this helped. flawless luck