. TM 5-5420-226-20-1 DETAILED TROUBLESHOOTING PROCEDURE SUPPORT SYSTEM -   PERSONNEL HEATER Symptom-74 PERSONNEL   HEATER   Hi/LO    SWITCH   WILL   NOT  CONTROL   HEATER (BLOWER   RUNS  IN  ONE  OR  BOTH  ON-HI,   ON-LO   SWITCH   POSITIONS). ~ NOT, This   procedure is to  be  performed by two persons. The lead person is referred to  as  the   first   technician and shall   direct    the   activity of  the   second person called    the   second technician. PERSONNEL . n HEATER Q FUEL PUMP > \ HEATER TO BASKET DISCONNECT a u# HARNESS CONNECTOR P ~Check for    personnel heater blower runnin9”  with PERSONNEL HEATER Hi/LO switch in   ON-LO position. Second Technician (Operator’s Station) l   Set   HEATER MASTER switch OFF. l   Set   MASTER BATTERY switch OFF First Technician (Personnel Heater) l   Disconnect heater to   basket disconnect harness connector (CKT 402)   from   personnel heater    fuel   pump. Second Technician (Operator’s Station) l   Set   HEATER MASTER switch ON. l   Set   PERSONNEL HEATER HI/LO switch ON-LO. (CKT    402) ‘‘ HEATER / ? PERI%ONNEL MASTER HEATER SWITCH Hi/LO SWITCH - TA107392 4-703