TM5-4210-229-14&P 4-22.  INVERTER MAINTENANCE (Continued). NOTE To allow twin agent 4x4 firefighting truck to be operational while inverter is out, continue as follows. i. Attach   adapter   harness   located   on   the   small control  harness  (4)  to  printed  circuit  board  con- nector located in the control box (3). j. Mount the control box (3) to the inverter bracket using     the     control     box     mounting     hardware. Ground    green    ground    wire    on    the    mounting hardware. k. Separate  the  red  and  black  power  harness  con- nectors (5) and plug them into each other to con- nect the alternator to the batteries. l. The voltage regulator in the control box (3) con- trols  the  vehicle  alternator  while  inverter  is  not operational or not installed. m. Connect  positive  and  negative  terminals  to  bat- teries. INSTALLATION NOTE If firefighting truck was wired to operate without  inverter,  begin  installation  pro- cedures  as  follows.    If  not,  begin  in- stallation procedures at step d. a. Disconnect  the  alternator  from  the  batteries  by unplugging   the   red   and   black   power   harness connectors. b. Remove   the   control   box   (3)   from   the   inverter bracket  by  removing  the  control  box  mounting hardware.    Remove  the  green  ground  wire  from the mounting hardware. c. Disconnect adapter harness located on the small control   harness   from   the   printed   circuit   board connector located in the control box (3). d. If   removed,   attach   brackets   (9)   to   inverter   (6) using four washers (11) and bolts (10). e. Position  inverter  (6)  into  compartment  and  se- cure  with  four  washers  (8)  and  mounting  screws (7). f. Remove   tags   and   connect   two   circuit   breaker wires to inverter (6). g. Connect  control  (4)  and  power  harness  (5)  on rear of inverter. h. Install control box (3). i. Install   four   lockwashers   (2)   and   screws   (1)   to control box (3). j. Connect remote control plug. k. Connect  positive  and  negative  terminals  to  bat- teries. TEST a. Run  engine  at  approximately  1500  rpm  with  in- verter operating at 120 VAC output. b. Apply normal AC load.  If not available, simulate load with equivalent wattage and type of load. c. If  AC  load  does  not  operate  properly,   inverter output  voltage  drops  more  than  10  volts,  or  in- verter shuts off, remove AC load. d. If   unable   to   achieve   stable   operation,   refer   to paragraph 4-11. 4-36