Coleman Mach 15
 

Hello I have less then a year old Colman Mach 15 unit in my living room. When I have it in the auto cool setting when it gets to the temperature I have it set to only the compressor kicks on. No fan will turn on, after about 2 minutes it will kick off. But if u go to the thermostat and turn down the temperature it starts up and runs like it should, it will also runs normal if I put the system in on more where it stays on continuously, I wonder if it is the control board or thermostat that is acting up I replaced all capacitors in the unit with brand new ones, the bedroom has no issues whatsoever and there both in the same thermostat on the wall.

Start with the simple stuff, maybe you want to swap thermostats and see if the problem moves to your other unit? I installed Honeywell stats for both front & back units.