ARMY  TM  9-6115-644-24 AIR  FORCE  TO  35C2-3-446-12 MARINE   CORPS   TM   09249A/09246A-24/2 TABLE  2-6. Unit  Troubleshooting  -  Continued MALFUNCTION TEST   OR   INSPECTION CORRECTIVE    ACTION Step 2. Test  for  defective  FREQUENCY  meter  (HERTZ),  paragraph  2-28-2. a. If  defective,  replace  FREQUENCY  meter  (HERTZ),  paragraph  2-28. b. If FREQUENCY meter (HERTZ) is not defective, and trouble persists, notify next higher level  of  maintenance. 23. AC  VOLTMETER  (VOLTS  AC)  VOLTAGE  FLUCTUATES. Step 1. Check  for  loose  electrical  connections,  refer  to  Electrical  Schematic  FO-1. a. If  no  loose  connections,  do  step  2. b. If  loose  tighten  electrical  connections. Step 2. Test  for  defective  AC  Voltmeter  (VOLTS  AC),  paragraph  2-31-2. a. If AC Voltmeter (VOLTS AC) is not defective, do step 3. b. If  defective,  replace  AC  Voltmeter  (VOLTS  AC),  paragraph  2-31. Step 3. Test  for  defective  VOLTAGE  adjust  potentiometer,  paragraph  2-34-3. a. If  VOLTAGE  adjust  potentiometer  is  not  defective,  do  step  4. b. If  defective,  replace  voltage  adjust  potentiometer,  paragraph  2-34. Step 4. Test  for  defective  AM-VM  transfer  switch,  paragraph  2-39-3. a. If  AM-VM  transfer  switch  is  not  defective,  do  step  5. b. If  defective,  replace  AM-VM  transfer  switch,  paragraph  2-39. Step 5. Check  for  defective  load  measuring  unit,  paragraph  2-65 a. If  defective,  replace  load  measuring  unit,  paragraph  2-65-2. b. If load measuring unit is not defective, and trouble persists, notify  next higher level of maintenance. 24. FREQUENCY    METER    (HERTZ)    FREQUENCY    FLUCTUATES. Step 1. Check  for  erratic  engine  operation. Refer  to  Malfunction  4  “Engine  Runs  Erratically  or  Stalls  Frequently.”  If  engine operating  property,  do  step  2. Step  2. Test  for  defective  frequency  transducer,  paragraph  2-52-2. a. If frequency transducer is not defective, do step 3. b. lf   defective,   replace   frequency   transducer,   paragraph   2-52. Step  3. Test  for  defective  FREQUENCY  meter  (HERTZ),  paragraph  2-28-2. a. If  defective,  replace  FREQUENCY  meter  (HERTZ),  paragraph  2-28. b. If FREQUENCY meter (HERTZ) IS not defective, and trouble persists, notify next higher  level  of  maintenance. 2-25