TM 5-5420-226-20-1 ( Symptom-66 ~NoTE— If   the    problem is   with    the    left    side service lamp check the left side intermediate connectors. If  the   prob- lem is   with the right side service lamp, check the right side intermediate connectors. ~ Check front    accessory harness (CKT    18)   at intermediate connector for   electrical power. First  Technician (Operator’s Station) l   Set   MASTER BA1’TERY switch OFF. Second Technician (Front of   Vehicle) l   Install    headlight assembly (page 10-172). Second Technician (Front of   Crew Compartment) Disconnect intermediate connector (CKT 18)   of front accessory harness from dual headlight base harness connector of   bad    service lamp. Connect red    probe of   meter to   front accessory harness connector (CKT 18)   of   bad    service lamp and    black probe to   ground. First Technician (Operator’s Station) l   Set   MASTER BATTERY switch ON. Second Technician (Front of   Crew Compartment) l   Check    if  meter   indicates 18  to   30   volts    dc. Does    meter indicate 18  to   30   volts    dc? DETAILED TROUBLESHOOTING PROCEDURE SUPPORT SYSTEM -   VEHICLE LIGHTING FOR CLARITY QUADRANT (Continued) ASSEMBLIES NOT SHOWN 0- n l 0 II I TO    VEHICLE GROUND L ~\c’Rcuw . INTERMEDIATE z% ELECTRICAL ~“ ,.r,A?sYlf I I_CONNECTORS (LEFT SIDE   SHOWN) ( Repair    dual   headlight base harness (page 10-298). I l   Inspect front    accessory harness for   bent/broken connector contacts or   loose CKT    18  wire    at   rear   of connectors. l   Repair   connectors if defective. (page 10-298). l   If  connectors are   not defective, notify support maintenance of   a  defective front    accessory harness. l   Connect front    accessory harness intermediate connector. -. .,.  ”-. “1A1U(5: 4-649