TM-9-2320-280-20 HMMWV Technical Manual Unit Maintenance Volume 1 Download
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TM 9-2320-280-20-1 Description: BATTERY RESISTANCE CHANGE TEST #75 This procedure measures the change of battery resistance. Test requires DCA hookup only. Typical Applications: Evaluate batteries in Cl engines with VTM powered from batteries of vehicle being tested. Test Procedure: 1. Disconnect fuel solenoid wire 54A to prevent starting. 2. Make sure all vehicle accessories are off. 3. Set TEST SELECT switches to 75. 4. Press and hold TEST button until CAL appears on display. 5. Release TEST button and wait for offset value to appear on display. If offset is within the -150 to 150 range, proceed. If not, go to DCA Troubleshooting Procedure. 6. Press and release TEST button. 7. When GO appears on display, engage starter for 2 seconds or until one of the following appears on the display OFF .9.9.9.9 A number An error message 8. Observe displayed value (milliohms/second). The limit is 50 milliohms per battery pair. A lower number is better than a higher one. Pre-Test Procedures: Run Confidence Test. Warm up engine to operating temperature. Turn off all electrical accessories. Possible Error Messages E002 Transducer not connected. E005 Offset not performed. E006 VTM does not detect battery voltage. E013 VTM cannot use data received. E020 No first peak information was detected by the VTM. E021 VTM cannot calculate result because current is over current probe’s range. NOTES If .9.9.9.9 is displayed, the battery resis- tance change value is beyond the range of the VTM and cannot be measured with the VTM. If E013 is displayed, then check battery connections and correct as necessary. Repeat Step 6. If E013 persistes after 3 tests, VTM cannot perform test. 2-748