Arrived to do a performance maintenance. Set system for cooling. Measured the systems static pressure measured a temperature split between return and supply air. Found that the system is operating with failing static pressure and is only cooling 10 degrees. Checked interior of the furnace for cleanliness. Found bacterial growth present on the evaporator pan. While checking the evaporator coil noticed some damage on the furnace heat exchanger. After inspecting further found that the heat exchanger is cracked, making the furnace unsafe to operate in heat mode. Went outside and verified refrigerant levels. Found that the system is low on charge indicating that there is a leak in the supposedly sealed system. Verified operation of all electronic and mechanical components. Found that the contactor outside is charred and appears to be throwing a spark. Found that the compressor is drawing close to its maximum rated amp draw. This is a symptom of the end of the compressors life. Spoke with ho