October 2019 Service and Repair ManualControl SystemPart No. 1280490GT S® -80 XC ™ • S® -85 XC ™ • S®-80 HF • S®-85 HF 271-7 H ow to Replace the Dis pl ay C ontroller (D ISC ON) Module1-7How to Replace the DisplayController (DISCON) Module1 Push in the red Emergency Stop button to theoff position at both the ground and platformcontrols.2 Disconnect the negative terminal from thestart battery and auxiliary battery, if equipped.Illustration 11 ground box lid2 DISCON gasket3 DISCON4 8/32 nylock nuts5 #8 flat washers6 ribbon cable7 DISCON door8 Torx head screws3 Open the ground box lid (1) and disconnectthe wire harness going to the display controller(DISCON).4 Remove the DISCON door from the back byloosening the four Torx head screws (8) andremove the two ribbon cables (6) connectingthe ground box overlay to the DISCON.Note the orientation of the cables for reassembly.5 Remove the DISCON from the ground controlbox lid by removing the five hex nuts andwashers (4, 5). Discard the nuts and washers.Note the lanyard attachment point for reassembly.6 Remove the old DISCON gasket (2) from theground box lid and clean the lid surface fromany dirt, oil or old adhesive residue. Use a99% solution of isopropyl alcohol to clean thesurface. Allow the surface to completely dry.Note: Both the ground box lid and new gasket mustbe 70° F / 21° C or higher at the time of application.Application of the new gasket at lowertemperatures is not recommended.7 Peel the adhesive protective film from theback of the new gasket. Carefully line up thenew gasket over the ground box lid, makingsure the cutouts for the LCD screen, ribboncables and mounting studs are centered andlining up with the gasket. Apply the new gasketto the ground box lid and work from the centerout to eliminate air bubbles and make sure allthe gasket edges are securely fixed.Note: Once applied it is not recommended to lift thegasket and attempt to reposition it.
