As it stands now my ac compressor and main blower turn off simultaneously. A thermometer at the first vent from the unit reads 45 degrees. I can manually turn the blower on and get more of that residual cold air in the house. I’d like to do it automatically. I’ve read the HVAC unit manual and looked over the unit but don’t see any adjustments to make that happen. How can I do this? 25 year old HEIR furnace and Tempstar condenser.