The outside wiring into our air conditioning unit became disconnected when we did the lawn. Do I connect the white wire to the white and the red and blue to the black?

Stratmando

I would pull off cover of inside unit. If to compressor unit, may find only a Pair of wires being used.

T-Top

Most techs will use the red and white wires for the contactor and the third wire is not used. Turn power off to A/C and furnace(so you dont blow a transformer or fuse) Go white to white and red to black. Turn power back on and see if it works. If the two wires outside was shorted together its a good chance the transformer or fuse was blown.