From "Amtrak Maintenance Training Manual for Superliner Cars, 1977"
"An equipment compartment is located on either end of the car with access only from the outside. The equipment compartment on the "A" end houses an air conditioning unit, hot water tank, two 250 gallon potable water storage tanks, a water raising pressure reservoir, heater box, exhaust blower and a waste treatment system. The equipment com-partment on the "B" end houses an air conditioning unit, main and auxiliary reservoir air storage tanks, a battery charger and an exhaust blower. The batteries are accessible by opening its compartment doors. A utility room also located on the "B" end is used for storage.An equipment compartment is located on either end of the car with access only from the outside. The equipment compartment on the "A" end houses an air conditioning unit, hot water tank, two 250 gallon potable water storage tanks, a water raising pressure reservoir, heater box, exhaust blower and a waste treatment system. The equipment com-partment on the "B" end houses an air conditioning unit, main and auxiliary reservoir air storage tanks, a battery charger and an exhaust blower. The batteries are accessible by opening its compartment doors. A utility room also located on the "B" end is used for storage."
This should answer your question.
Nick