Installed 8†and 9†dampers. Blowing less air to affected rooms. Customer is content with dampers being open half way. 2 system PCM. Checked blower motor amps. Checked inducer motor amps. Inspected duct work. Replaced air filter. Cleaned flame sensor. Checked electrical components. Checked mini split unit. Left side room is not keeping up. Room has 4 windows all facing sun and heat from downstairs unit is keeping room hot. Advised customer to leave system on cool and allow unit to drop temperature. Right side split is working fine. Noticeable temperature difference between the two rooms.