Nav lights

[Joe Noah]

The three nav lights do not work, but the cockpit lights do work on the rheostat. Also, the gear down llight dimms when the nav light switch is turned on.

Joe Noah, 1925

[N3322G]

Joe,

Welcome to the Forum - I noticed this is your first post.

Can you add a little more background on the nav light failure. Any recent work done on the plane - when was the last time you used them etc.

While I'm not a mechanic, several folks on the Forum are and may be able to pass along what to check for. I haven't had this failure yet so don't know the fix or what to look for.

[Zach Grant L1011jock]

First, check your nav light breaker. Depending on what model airplane, and what mod status you have, this could also be depowering your aux pump (s). The nav lights are one cirtcuit, the panel lights another, and the gear lights yet another circuit, they just all happen to have some functionality connected to the rheostat. Check your bulbs (yes not all should be bad...but I have seen it...).

After checking the nav light breaker (pull and reset) I would look at the switch on the back of the rheostat. The nav light switch is actually a simple switch that is engaged by an arm when you turn the knob the first bit. It is a two pole switch. One pole for dimming circuit for gear lights, and other pole for turning on the nav lights. Make sure all contacts have power when the switch is on. If all the other stuff is correct, I'm going to bet there is no power to the switch in the light circuit, and finding the broken wire should be somewhere between the breaker and the switch.

-Zach

PS. For future reference it is much easier to answer specifics if you include the model year and model of Comanche that you are asking about. Some of this info may or may not be right for your model, it is a broad spectrum general approach. I am half guessing you have a twin with 3 position lights (most singles have 4 lights, two on the tail) but am not sure so included single info.

[Kristofer Duckett]

[Zach Grant L1011jock]