Table  1-2.  Troubleshooting  Chart—Continued Malfunction 6. Evaporator air output volume low. 7. Condenser air output volume low. 8. Air conditioner fails to heat. 9. Excessive noise. 4-13. Probable   Cause Corrective   Action c. Evaporate: fan speed switch set at low  speed. a. Dirty or damaged filter or louvers. b. Iced or dirty evaporator coil. c.  Defective  evaporator  fan. d. Defective fan motor. e. Evaporator fan speed switch set at low  speed. a. Dirty condenser coil or guard. b. Defective HIGH-LOW condenser fan thermostatic switch. c.  Defective  condenser  fan. d. Defective fan motor. e. Air outlet louvers stuck in closed position. a. Selector switch improperly ad- justed. b. Temperature   control switch set incorrectly. c. Dirty evaporator return air filter. d.  Defective  evaporator  fan  motor. e.  Defective  temperature  selector switch or mode selector switch. f.  Defective  heaters  or  wiring. g. Defective heater relay. h. Defective heater high temperature cutout thermostatic switch. a.  Evaporator  or  condenser  fan vibrating. b. Evaporator or condenser fan motor worn or defective. c.  Compressor  knocks  or  clatters. d. Reset switch to high speed. a. Clean or replace filter (para 4-17). Clean  or    replace    louvers  as required (para 4-18). b. De-ice and clean coil (para 4-24). c.  Replace  fan. d. Replace motor (para 4-38 and 4- 40). e. Reset switch to HIGH speed. a. Clean coil and guard (para 4-23). b. Replace switch (para 4-41). c. Replace fan. d. Replace motor (para 4-38 and 4- 40). e. Free louvers and control cables. Adjust control or refer to direct support maintenance if actuating cylinder is not   functioning properly. a. Reset selector switch to LO-Heat or HI-heat (para 2-10). b. Reset switch (para 2-10). c. Clean filter (para 4-17). d. Replace motor (para 4-38 and 4- 40). e. Replace defective switch (para 4- 44 thru 4-48). f. Tighten connections and repair damaged wiring. Replace defective  heaters  (para  4-35). g. Replace defective relay (para 4-50 thru 4-54). h. Replace defective thermostatic switch (para 4-34). a. Tighten fans on shafts. Tighten all mounting screws. b. Replace worn or defective motor (para 4-38 and 4-40). c. Stop air conditioner and report condition  to  direct  support maintenance. Section   VI.   RADIO   INTERFERENCE   SUPPRESSION General Methods Used to Attain Proper power  supply.  Capacitors  (fig.  4-1)  are  located Suppression Essentially, suppression is attained by providing a low resistance path to ground for the stray currents. Methods  used  include  shielding  ignition  and  high frequency wires, grounding the frame with banding straps  and  using  capacitors  and  resistors. 4-14.   Interference   Suppression   Components The   control   module,   junction   box   and   electrical system  components  are  grounded  to  the  housing. The  housing  is  connected  to  a  ground  wire  in. across  the  rectifier  terminals.  Grommets  are  in- serted in the heat support bracket to isolate heating elements  from  bracket  to  prevent  metal  to  metal contact  and  scraping  during  expansion  and  con- traction   of   heating   elements.   Power   inlet   cover chains are encased in shrink type tubing to prevent rattling  of  chain  links. 4-15.  Replacement  of  Capacitor a.   Removal. (1)  Remove  front  top  cover  of  air  conditioner. 4-5