TM 5-5420-226-20-1 Symptom-72 DETAILED TROUBLESHOOTING PROCEDURE ^STEPo^1CONTINUED SUPPORT SYSTEM -   PERISCOPES T (Continued) First l l l l Technician (Commander’s Station) Remove floor access cover (at    Commander’s feet) (page 17-9). Disconnect front accessories harness connector (CKT 5 16)   from IR    powerpack input connector of   defective IR    periscope. Set   multimeter to   measure 18  to   30   volts dc,   or   use STE/ICE Test No. 89   (page 4-81). Connect red   probe   of  meter    to  front    accessories harness connector (CKT 5 16)  and    black probe to   ground. Second Technician (Operator’s Station) l Set   MASTER BATTERY switch ON, l Set   NIGHT VISION switch ON. First Technician (Commander’s Station) l Check if  meter indicates 18  to   30   volts    dc. Does    meter indicate 18  to   30   volts    dc? I VEHICLE GROUND II INPUT CONNECT?R \ ~---A— \ \ IR POWER  PACK ( f >~_._(fq CONTACT h ) l inspect front    accessories harness for   bent/broken connector contacts or   loose CKT   516   wire    at   rear   of connectors. s Repair    connectors if  defective (page 10-298). l if  connectors are   not defective, notify support maintenance of   a  defective front    accessories harness. l Reconnect front    accessories harness connector to   iR powerpack. l Instail floor    access cover (page 17-9). 4-682 .