TM 1-1520-238-T-7 10–170 Change 5 10–53. FUEL TRANS CIRCUIT BREAKER – DOES NOT STAY CLOSED 10–53 Tools: Nomenclature Part Number Tool Kit, Electrical SC518099CLA06 Repairer’s Multimeter, Digital AN/PSM-45 Personnel Required: 68X Armament/Electrical Systems Repairer One person to assist References: TM 1-1520-238-T-6 TM 1-1520-238-23 Equipment Conditions: Ref Condition TM 1-1520-238-23 Access provisions – L40 door removed 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. Attach positive meter lead to P174–A11 and check for short to ground. Does short exist? YES Go to step 2. NO Go to step 4. 2. Detach P940, check for short between P174–A11 and ground. Does short exist? YES Go to step 3. NO Replace fuel transfer air control valve (TM 1-1520-238-23). 3. Detach P429, check for short between: P174–A11 and ground, P444–A11 and ground. Does short exist? YES Repair shorted wire between: P174–A11 and P429–B4, P444–A11 and P940–2. Go to paragraph 10–47. NO Repair shorted wire between (A402): J23–B4 and TB2–13–M, J31–A11 and TB2–13–L. Go to paragraph 10–47. 4. Attach positive meter lead to P174–A9 and check for short to ground. Does short exist? YES Go to step 11. NO Go to step 5. 5. Check for short between (A402)J2–D and ground. Does short exist? YES Go to step 6. NO Refer to TM 1-1520-238-T-6 to troubleshoot circuit protection system (dc essential bus 2 – pilot station). 6. Check for short between (A131): J1–B11 and chassis ground, J1–B2 and chassis ground, J1–A11 and chassis ground. Does short exist? YES Replace pilot FUEL panel (TM 1-1520-238-23). NO Go to step 7. 7. Check for short between (A179): J1–A3 and chassis ground, J1–A5 and chassis ground, J1–A6 and chassis ground. Does short exist? YES Replace CPG FUEL panel (TM 1-1520-238-23). NO Go to step 8.