I know there is a short somewhere and i ve read on multiple posts to remove the wires from the 24 volt terminal block w r g c y and start putting them back one by one until the fuse blows again and then you ll find your problem.
Furnace control board 3a fuse blowing.
Go to outdoor unit.
The most probable of these are 1.
2 reconnect all wires previously disconnect at control board.
Loose electrical cables there could be loose electrical cables inside the circuit box or somewhere in your ac which could be causing a short circuit.
When a thermostat wire touches the metal frame of the furnace it can deliver more voltage than the wires are designed to handle.
This will blow the fuse on the control board causing the draft inducer to not start which then stops the rest of the furnace functions from working properly.
The 3a fuse had blown again.