The indicator on this machine is broken.
Please look at the temperature gauge.
表示器 is a more general term for a display unit, while 指示器 specifically indicates a measured value or status.
インジケーター is a common loanword for 'indicator', often used in casual or IT contexts, while 指示器 is more formal and technical.
direction indicator; turn signal
Standard kanji spelling for 'indicator' (device).
Irregular kanji usage; 機 (machine) is sometimes used instead of 器 (device).
Compound of 指示 (instruction, indication) and 器 (device, instrument).