Complete 1 system furnace repair and preventative maintenance check. Customer complained of dead rodent smell. Found dead rat at bottom of the blower wheel. Pulled and cleaned blower wheel and removed rat. Found blower capacitor leaking oil, recommend a repair. Filter setup is not proper and is not protecting equipment from dirt. Evaporator coil is very dirty and will cause problems with the system. System has no water safety whatsoever to protect floors from water damage. Evaporator coil is very rusty and corroded and likely to leak. System runs on r22 refrigerant which has been phased out by the epa. Two ducts have holes in them due to rats chewing into them. Recommend repair. System is heating at this time.