TM 10-3930-669-20 2.  AMMETER GIVES NO OR INCORRECT READING (CONT). KNOWN INFO Batteries OK. Wire 11 OK. POSSIBLE PROBLEMS Ammeter ground wire faulty. Wire 12 faulty. Ammeter faulty. KNOWN INFO Batteries OK. Wire 11 OK. Ammeter ground wire OK. POSSIBLE PROBLEMS Wire 12 faulty. Ammeter faulty. TEST OPTIONS Continuity test. STE/ICE-R #91. REASON FOR QUESTION If    continuity    is    not    present, ammeter ground wire is faulty. TEST OPTIONS Voltage test. STE/ICE-R #89. REASON FOR QUESTION If 22 to 24 vdc are not present, sensor wire 12 is faulty. ¬ ¬ 2-134