TM 1-1520-238-T-6 9–272 9–82. LT SRCH/LDG CIRCUIT BREAKER (CB22) – DOES NOT STAY CLOSED 9–82 Tools: Nomenclature Part Number Tool Kit, Electrical SC518099CLA06 Repairer’s Multimeter, Digital AN/PSM-45 Personnel Required: 68X Armament/Electrical Systems Repairer References: TM 1-1520-238-23 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. CAUTION If access to search light unit is required, unit must be suspended with suitable lockwire to prevent damage to electrical wiring. Failure to comply could result in damage to equiptment. 1. On pilot center circuit breaker panel, open LT SRCH/LDG circuit breaker (CB22). Check P5-4 for short to ground. Does short exist? YES Refer to paragraph 9–263 to troubleshoot circuit protection system (dc emergency bus – pilot station). NO (AAQ) Go to step 2. (AAJ) Go to step 6. 2. (AAQ) Check for short between (A402)J29-4 and ground. Does short exist? YES Go to step 3. NO Go to step 4. 3. Detach wire K320-B. Check K320-B for short to ground. Does short exist? YES Replace search light relay K320 (TM 1-1520-238-23). NO Repair shorted wire between (A402): J29-4 and J29 SP1, J29 SP1 and XK320-B. Go to paragraph 9–80. 4. Detach wire DS11-9. Check wire end for short to ground. Does short exist? YES Go to step 5. NO Replace landing/search light (TM 1-1520-238-23). 5. Detach wire K320-A. Check wire end for short to ground. Does short exist? YES Repair open wire. Go to paragraph 9–80. NO Replace search light relay K320 (TM 1-1520-238-23). 6. (AAJ) Check (A402)J29-4 for short to ground. Does short exist? YES Go to step 7. NO Go to step 9. 7. Detach wire (A402)TB1-1/2-F. Check wire end for short to ground. Does short exist? YES Go to step 8. NO Repair shorted wire between (A402): J29-4 and J29 SP1, J29 SP1 and TB1-1/2-E. Go to paragraph 9–80.