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Gear unsafe/in-transit light not illuminating during gear operation

Hello, the aircraft is a 1978 V35B. We noticed on the last flight that we did not get the red "in-transit/unsafe" light during gear operation. Upon further examination utilizing the gear "dim/test" switch, the red light will illuminate as normal, however no light is showing during gear transition. Three green indicators are operating as normal. Any suggestions on where to start? Responses greatly appreciated!


Model: Bonanza V35B
Aircraft Serial Number: D-10170
Posted 11/21/2023 - 3 months ago

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I have attached the wiring diagram manual section for the gear position lights.

Normal circuit in that voltage is applied to the light, and it finds its ground either through the push-test function, or a series of conditional switches. First is the left up limit switch; if the gear is not up and locked, this switch allows the voltage path to the next switch, the landing gear down light switch; if it is not down and locked the ground is made. The down light switch is the same switch that supplies the final ground for all three green lights; so if they are working correctly, it may be an open connection somewhere along the line. As they say, follow the voltage.

ABS Technical Advisor


33-36 28V WIRING DIAGRAM MANUAL P_N 35-590102-9.pdf - 397.1 KB

Posted 11/21/2023 - 3 months ago

Gear unsafe/in-transit light not illuminating during gear operation