TM  10-3930-638-24&P 2-32.   HORN   AND   BACK-UP   ALARM   MAINTENANCE   (cont) b. Horn Switch (cont). LOCATION ITEM ACTION REMARKS STEP LEANING  (cent) 2 3 4 INSPECTION 5 6 7 8 TESTING 9 Wear safety glasses when drying parts with compressed air. Failure to do so could cause serious injury to eyes and possible blindness. If you hurt your eyes or if a foreign object is blown into  your  eyes,  seek  medical  attention  immediately. Contacts (3 and 5), spring (4) and screws (6) Cover (1), button (2) and base plate (7) Connector (8) and terminal (11) Spring  (4) Contacts (3 and 5) Cover (1), horn button (2) and base plate (7) Grommet (9) Horn wire in steering column INSTALLATION/REPLACEMENT 10 Steering  column a. Grommet (9) and wheel b. Harness connector (8) C. Base plate (7) d. Three tapping screws (6) e. Spring contact (5), spring (4) and contact cup (3) f. Horn button (2) and cover (1) Clean Clean Clean Inspect Inspect Inspect Inspect Test Install Push in Position Install  and tighten Position Install Use  cleaning  solvent  P-D-680. Dry thoroughly with compressed air Wipe with a clean, dry cloth Use cleaning solvent P-D-680 on termina and connector only Replace if coils bent or broken Replace if cracked, corroded or damaged Replace if cracked, worn or damaged Replace  if  worn  or  deteriorated Set  ohmmeter  to  lowest  resistance  range and connect leads to horn wire at ferrule (10) and terminal (11). Replace horn wire if ohmmeter indicates more than 0.5 ohm (notify direct support maintenance). Column  terminal  (11) On steering wheel Until base-plate (7) is securely mounted On base plate (7) Depress and rotate clockwise to lock tabs on base plate (7); then release 2-178