Inspected system and found multiple reasons for way furnace was overheating. Indoor coil was dirty and needed cleaned. Several of the fins are damaged beyond repair but it seems to be allowing proper air flow through. Blower wheel was filled with hair and debris. Cleaned flower wheel. Blower motor was also FULL of debris beyond salvageable. Bearings inside motor were also heavily worn. Replaced blower motor. Cleaned out furnace flue which had at least one dead mouse inside. Air return is also too small for system which means system cannot use pleated filters and operate normally. System is going to need fiberglass filters only. 10x20x1 and 12x20x1. System is operating normally at this time.