TM 1-1520-238-T-5 7–119 7–39. TAIL WHEEL ADVISORY LIGHT – IS NOT LIGHTED 7–39 Tools: Nomenclature Part Number Tool Kit, Electrical SC518099CLA06 Repairer’s Multimeter, Digital AN/PSM-45 Personnel Required: 68X Armament/Electrical Systems Repairer (2) References: TM 1-1520-238-T-6 TM 1-1520-238-23 Equipment Conditions: Ref Condition TM 1-1520-238-23 Tail landing gear lock actuator target adjustment – completed Access provisions – L90 door open WARNING Turn off power before detaching or attaching wires and connectors. High current 28 VDC or 115 VAC is present. Failure to do so could result in death or serious injury. 1. Check for 28 VDC at P748–C. Is voltage present? YES Go to step 2. NO Go to step 3. 2. Check for open between P748–A and P748–B. Does open exist? YES Repair open wire. Go to paragraph 7–21. NO Replace multi–channel dimming controller (TM 1-1520-238-23). 3. Check for 28 VDC at P754–A. Is voltage present? YES Go to step 6. NO Go to step 4. 4. Check for 28 VDC at P1–15. Is voltage present? YES Go to step 5. NO Refer to TM 1-1520-238-T-6 to troubleshoot circuit protection system (dc emergency bus – pilot station). 5. With TAIL WHEEL switch set to UNLOCK, check for open between (A331): S1–2 and S1–3. Does open exist? YES Replace TAIL WHEEL switch (TM 1-1520-238-23). NO Repair open wire between: P754–A and (A331)S1–3, (A402)TB2–9–A and (A331)S1–2, (A402)TB2–9–D and (A402)J1–15. Go to paragraph 7–21. 6. Check for open between P754–B and ground. Does open exist? YES Repair open wire between P754–B and GS682–F. Go to paragraph 7–21. NO Go to step 7.