I changed my thermostat and now my outside unit won’t turn on

I have a trane heat pump and A/C unit outside and a trane unit inside. I had to replace my thermostat because the one I had, didn’t have emergency heat option on it. I turned off the breaker and installed the new thermostat. Afterwords, only heat would work. The fan worked and the heat would blow, but today we needed the A/C on, and when we turned it on, heat still came out. I looked at the breakers and nothing was tripped. I decided to try the old thermostat to see if it would fix the A/C. After I reinstalled the old thermostat, the fan works and it is t blowing hot air out, but the A/C still isn’t working. I just don’t know where to go from here. Is there a fuse inside the outside unit that could be blown?