Wayne-mg. Heater and Air Conditioner Electrical System How it Works . . . The air conditionenheater consists of six basic electrical components: I blower motor I compressor clutch coilengages compressor with drive I de-icing switch which controls compressor operation during air conditioner operation by sensing temperature ol evaporator core blower speed swttch in series wtth resistor to vary blower speed blower motor resistor that changes current to permit ditlerenl blower speeds system OFF-ON switch and clutch switchpart of vacuum control that turns blower on and also ener- gizes clutch circuit in NC position Trouble-Shooting ll blower motor does not operate in any blower swltch position . . . I check fuse 3 I check that ignition switch is in RUN position I check feed to luse3 li blower motor still inoperable . . . I set blower switch at HIGH I check lor power at terminal wtre 270 (bk/Y) in Connector 604 pl blower motor resister pack ll there is power at terminal or wire Z70 (bk/y) in Connector 604 . . . I disconnect connector 0604 I check for continuity between connector terminals If there is no continuity , . . I inspect motor molded connector I check motor ground wrre ll connector is OK I replace mctor il connector and ground wtre OK If there is no power at terminal or! wire 27D (bk/y) In Connector 604 . . . I check continuity between connector and blower switch It there is no continuity. . . I repair wiring If there is continuity . . . I check lcr power to blower switch "there is powertoblowerswitcti. . . I replace blower swrtch If the blower operates in some but not all switch positions . . . I position blower switch at LOW I check lor power at terminal at wrre 288 (r bk) in coneclor C604olblower motor resister pack I position blower swttch at Med-Low I test for power at terminal 0! wtre 268 (r/bk) In connector 0604 oi blower motor reststor I position blower motor switch at Med-High I test lor power at terminal ol wire 269 (bl/r) In connector 0604 ol blower motor resister pack Ii there is power at all three . . . I replace resistor pack It there ls no power at one or more terminals . . . I unplugconnectorlrom blower switch I checklorcontinuityatBIowerSwttch where there was power I check all positions. except OFF If any tested switch position has no continuity . . . I replace swnch It clutch does not engage. . . I check for power at clutch connector ll there is no power at clutch connector . . . I check for power at clutch switch on control assembly ll no power at clutch switch . . . I check clutch switch for continuity I replace it there is no continuity It power at clutch switch . . . I Check De-icing switch lor continuity replace it necessary If power at clutch connector . . . I Perform clutch coil current draw test (see Shoo manual) 2m DKY 25; or r , 253 r on Blower Resistor Connector 0604 (Both A/C and Heater Only) Blower Switch Continuity Connections :1 5i V Blower Speed - Terminal Connections Low l 5 l2) Med tow l 3th <2ri5i Med -Hi B-Mier lzlrlllrlil Hrgn l arnsmz l t2) lli'l4l Component Component Location Blower Motor Blower Motor Resistor Connector C604 Connector Coos Connector cat 3 Cornector cots Spine 5603 SpliEE s7ot Ground Gsot RH crowsr nousrng on englne center lorwaro On engine center ionrtrsm Near AtC evap thermostat Neal blower motor resistor Attached to healer case A C FUNCTlON w Tran 5) prior; 7i Delrosi rct em rot not when ignition Switch in Run isas Page 9) Eln 35 Amos 1 zec r on 255 ibk Engine Compartment. at an oasn panel Flt-l stoe centric instrument panel in engine compartment center or vehlcle near oasn oanei DE-ICING swim a case 5W" EA r , Low 2r Meow at Modelgh ., thn nt /_ 4w clo Cal 0an Lil Cain To Carb Thrattie by Cnnrlo' Sclenon recs P192 9 t A c otorcn SDLENOlD a owEn MOYQR 'Note: There are two ly s ol blower switches used. erminal Identication is on the connectors. One type uses codes B-M1 etc. (1 SI column), and the second type uses codes (2)45) etc. (2nd column). I 41