Press-to-Test / Dimmable Indicator Lights

These MS25041-series mil-spec indicators replace the original amber and green gear position indicators; the white in-transit light on the later airframes is an available option. Both the panel mounting ½” hole and the bulbs remain the same as the original. Expect an experienced installer to do the installation in 1 to 1-1/2 hours; an adjacent instrument hole is required for access.

Operation of the test function is activated by depressing the lens; dimming by twisting the lens clockwise. Only the amber has this dimming function; the green lighting is not so intense as to require that. This non-dimming function also helps to avoid an inadvertent daytime problem after a night flight.

Added wiring consists of a circuit to the existing 5-amp indicator lights’ circuit breaker for the bulb-test function, and a ground circuit. Kit contents include the indicators properly assembled with MS22759/16-20 Tefzel wire marked per the airframe specification using the Kingsley hot-stamp process. Marked wire for the added circuits, terminals, bulbs, PVC sleeve to cover the knife terminals, nylon cable ties for security, instructions and schematic are also included.


  1. Safety – adds bulb testing capability.
  2. Dimming – is independent of the electrical circuit.
  3. Safety – eliminates the hard-to-see green light during night operations.
Landing gear indicator lights