To remove and replace heater unit on the 1982 and later Sunny 200SX and 240SX starting with TEMP lever on the HOT position and removing coolant. Remove the heater hoses from the driver's side of the unit by unbolting them. To gain access to the mounting bolts it is recommended to disconnect the front seats: the use of tools to pry off the T-shaped plastic covers, protecting the seat runners will be helpful next, one has to detach the console box and floor carpets. Second, remove the instrument panel lower covers together with the lower cluster lids and the cover on the both driver's and passenger's sides. Take out the left-hand side ventilator duct, radio, sound balancer, and stereo cassette deck if mounted in your car. Remove the instrument panel-to-transmission tunnel stay, rear heater duct to floor, and center vent hopper next to the left and right-hand side air outlet vents. In the first step, you should disconnent the wire harness connection and unbolt the screws of the heater unit and control assembly. For reinstalling, set the heater assembly in its place fixing it with retaining bolts, join all the cables of electrical and heater control, and put back the air guides, center ventilator duct and rear heater duct along with rest of the part if needed for installation. If the instrument panel lower covers, floor carpets, console box, and seats were removed, they should be reinstalled. Disconnect the heater hoses from the heater core and remove the clamps, use new clamps to reconnect the hoses, reconnect the ground cable of the battery, and coolants should be replenished. Last, turn the engine for about half an hour and set the heater on to determine correct coolant level, examine for leakage and right working of the heater. In models with air conditioning, the evaporator core is placed in the engine compartment; therefore, there should not be any hurdle when unbonding the heater core. In refilling the cooling system always make sure that you relieve the cooling system of air. It is necessary to locate and unplug the negative battery cable, plus, it was necessary to remove the instrument panel, also to disconnect the heater hoses and vacuum lines and located in the engine compartment, together with the disconnection of the control lever, as well as the electrical connectors, to fully disconnect the heater control assembly. Take out the bolts and the heater unit assembly then place the heater unit and control assembly back in place as well as reconnect the hoses and the vacuum tube, take back the instrument, fill the cooling system and start the engine to see that everything is fine.
Posted by NissanPartsDeal Specialist 
