— TM   5-5420-226-20 DETAILED TROUBLESHOOTING PROCEDURE Symptom-76 SUPPORT SYSTEM -   PERSONNEL HEATER EXHAUST FUMES FROM PERSONNEL HEATER INSIDE VEHICLE. Exposure to exhaust fumes in    an enclosed area    can   be   dangerous to your   health. I This  procedure is  to  be  performed by two persons. The lead person is referred to  as  the  first   technician and shall   dirbct   the  activ~ty   of  the  second I nerson    called    the   second technician. I . \“ #   Check    external exhaust tube    for   damage or obstructions. First l l l l l Technician (Operator’s Station   ) Set    PERSONNEL HEATER Hi/LO switch OFF. Set    MASTER BATTERY switch ON. Set   VENTILATOR switch ON (TM 5-5420-226-10) and   allow    blower motor to   run   until    exhaust fumes    are cleared from vehicle. Set   VENTILATOR switch OFF. Set    MASTER BATTERY switch OFF. Second Technician (Right Front Fender) l   Look    into    opening    of  external    exhaust    tube    and    check for   obstructions. l   Check   external exhaust tube    for   damage. Is  external exhaust tube    obstructed or   damaged? VENTILATOR SWITCH ) l   Remove obstructions from external exhaust tube. l   If  exhaust tube    is  not obstructed, replace damaged external exhaust tube (page 18-22). TAI07408 4-719