TM 1-1520-238-T-4 4–131 4–49. ENGINE 1 – DOES NOT START 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 152FG Pilot References: TM 1-1520-238-23 TM 55-2840-248-23 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. With power applied, set and hold ENG START NO 1 switch in START position, check for open between: J21–17 and J21–18, J21–19 and J21–18. Does open exist? YES Go to step 2. NO Go to step 3. 2. Check for open between J21–17 and J21–19. Does open exist? YES Go to step 4. NO Go to step 6. 3. Remove relay (A402)K1–5/6. Set and hold ENG START NO 1 switch in START position, check for 28 VDC at (A402)XK1–5/6–X1. Is voltage present? YES Go to step 5. NO Go to step 7. 4. Check for open between (A330): J1–B11 and J1–B12. Does open exist? YES Repair open wire between (A330): J1–B11 and J1–B12. Go to paragraph 4–12. NO Repair open wire between: J21–17 and P977–B11, J21–19 and P977–B12. Go to paragraph 4–12. 5. Check for open between (A402)XK1–5/6–X2 and ground. Does open exist? YES Repair open wire. Go to paragraph 4–12. NO Replace relay (A402)K1–5/6 (TM 1-1520-238-23). 6. Check for open between: P21–17 and P45–17, P2 1–19 and P45–19. Does open exist? YES (ABY) Repair open wire. Go to paragraph 4–12. (ABZ) Replace wire harness (TM 1-1520-238-23). NO Refer to TM 55-2840-248-23 to troubleshoot engine ignition system.