Installation of Lotus Exige S2 heater fan / resistor block fix : Cars with Aircon
Requires : 1 x Heater fan resistor replacement package (Elise S2) (A120P0148S)
Time : Around six hours to complete this job. Clamshell removal is the starting point.
Basic Steps (with clamshell removed) :
(1) Discharge the aircon system from service point (requires removal of right rear air intake duct behind drivers door).
(2) Remove front clamshell, water cover, wiper motor bracket and fuse box.
(3) Loosen wiring loom and disconnect HVAC thermostat and fan motor cables.
(4) Remove large air hose / duct from outlet of heater maitrix (top) to car vents.
(5) Remove air con hoses to and from expansion valve (located on top /rear of heater matrix). Cover ports with tape to prevent damage.
(6) Gently bend the brake hose from master cylinder up and out of the way.
(7) Remove vacuum hose from servo (pull out the rubber stopper from servo case with hose)
(8) Remove water hoses into heater matrix (gently, the hoses will feel welded on but the connecting pipes are only packed into the top of the box with silicon sealant).
(9) Once clear, you should be able to unclip the heater assembly from the fan and withdraw the heater and evaporator unit diagonally in one piece.
(10) Remove the heater fan unit from the car. It is not unusal to find the floor of this chamber flooded.
(11) Remove silver resistor block from fan unit and discard.
(12) This is a good time to apply 12v direct to fan motor to ensure that motor is operational before you go to all the trouble of re-installing a defective one.
(13) Installation of the lotus mod. kit per the technical service bulletin that comes with the kit (drill and replace rivets)
(14) Assemble the heater fan and modified HVAC unit together and test for fit.
(15) Drill drainage holes into the 4 corners of the front HVAC chamber if you have not already done so.
Installation is the reverse. First locate the heater fan into oen end of the HVAC chamber. Then install the heater unit - NOTE : there is a small a/c drainage hose that needs to be reconnected to the bottom of the heater matrix whilst inserting the unit into the car. You can't see it, can barely feel it, and it's going to be slippery. Fun !
Finally, clip the heater and fan assembly together in situ, reconnect all hoses for water and check for leaks.
Repressurise aircon and check for leaks (mine leaked at the mounting point where the aircon pipe from the sill connects to the front pipework).
Finally reinstall clamshell and other components per the service manual.