Gear Indicator Lights 67 M20F

[bgpilot1]

What could cause the red and green gear indicator lights in a 67 M20F, johnson bar, to test ok but not illuminate otherwise?  Am I correct in assuming that the red light should be on whenever the gear is up?  Green light on whenever the gear is down.

Half way through the annual.  Going to jack the plane up tomorrow and test everything...will probably wish I had the one piece belly but that is for another day!

Thanks,

Barry

[MooneyMitch]

Jim is correct.  The gear indicator switch is located behind the panel, near the top of the J bar area.  The switch provides the power to both the red and green lamps.  There is no switch at the gear up floor lock.

With the gear up, the red light will be illuminated.  As the gear is locked in the down position, the green light will illuminate and the red light will extinguish.

I would check to see if the wires are connected properly to the switch and gear lamp terminals.  Check that the switch is peforming and adjusted properly.  Also check wire continuity between the swtich and lamp terminals. 

[Immelman]

Stick your finger up into the J-bar socket while in flight (or while on jacks and the gear is up) and you should feel a "click" as the switch closes. The red light should illuminate and green light extinguish right at that 'click' point -- no later.

My switch started to fail on me -- the green light was slow to come on and/or intermitent if actuated by the johnson bar. With my finger, I found that depressing the switch latch all the way to the stop caused the green light to illuminate. This was the result of the switch being worn out. I called LASAR and they sent me a replacement. It wasn't expensive. We then jacked the plane and I replaced the switch (an exercise in patience due to the cramped quarters) under A&P supervision.

The old switch showed that when the 'click' happened, the NO set of points went to some odd resistance.. 50 ohms or so, causing the itnermittent green light. The new switch had the NC side open and NO side close the moment the click occured.

Finally, when replacing the switch, you'll need to calibrate it (by bending the switch arm) so that it 'clicks' JUST when the j-bar gets into the position where it locks. You don't want it to prematurely show green.

[rob]

Barry, I think we crossed paths once. Do you keep your plane at AWM? Who's doing your annual?