Garmin GTR 225 Installation Manual

Also see for GNC 255: Pilot's guide

Contents

Garmin GTR 225 Installation Manual Manual pdf 69 page image

190-01182-02 GTR 225/GNC 255 TSO Installation ManualRev. B Page 6-156.5.4 Lighting Bus Interface CheckCAUTIONWhen 14 VDC or 28 VDC lighting buses are connected to the GTR/GNC, connection ofthe aircraft lighting bus to the incorrect input pins can cause damage to the GTR/GNC.Always start this test with the dimming bus at the lowest setting, and slowly increase thebrightness. If the brightness level on the GTR/GNC display does not increase as thelighting is increased in brightness, verify that the wiring is correct before proceeding.The display and bezel key backlighting on the GTR/GNC can track an external lighting/dimmer bus inputand use it to vary the display and bezel key backlight levels accordingly. This check verifies that theinterface is connected correctly.1. Ensure the lighting bus is set to its minimum setting.2. Slowly vary the lighting bus level that is connected to the GTR/GNC. Verify that the displaybrightness tracks the lighting bus setting. Continue to maximum brightness and verify properoperation.