Ac turns on for 2 min than shuts of for 45 sec than seems to cycle every 30 seconds it will run for 3 sec. Temp outside was 98. Turned Ac on last night when temp was down to 80 outside and Ac worked all night. Just had Ac installed 3 months ago

Sounds like the freon is low and AC is cycling. Should still be under warranty for the install.

Can you describe your thermostat for me? Was a new stat installed with the new a/c?