Changing out old thermostat to programing... now the a/c will not work
Where might the reset button be on a carrier unit?

I doupt if it is a outdoor reset problem. I would check the low voltage wiring for a error in instillation. If necessary trace the wires from the thermostat back to the furnace and make sure the color code is correct.

Did you jumper the red wire to both RC & RH? Another thing is to connect the red wire to the green and yellow. If the A/C comes on, the problem is in the thermostat. If not, the wiring or system.