Dim light indication in Annunciator Panel for "Gear Down"

[M20TN_Driver]

So i thought initially that it was just a burned out bulb, so I replaced it and still have a very dim indicator light for Gear Down.  Even when pushing the test button in I am getting just very faint/dim indication.  The gear is actually down and the football on the floor is lit and showing gear down properly.  I know the annunciator is a "convenience" indication for the gear, but I'd like it working properly.  

Any suggestions on this one?  I would have thought it was a wiring issue or something to do with the switch in that triggers the indicator IF the test button didn't also show a really dim indication.  And that friends is the issue--its so dim you cannot see if in daylight flight conditions.

[M20TN_Driver]

Nav lights are not on.  All lights are normal except that light.

 

[LANCECASPER]

5 hours ago, M20TN_Driver said:

So i thought initially that it was just a burned out bulb, so I replaced it and still have a very dim indicator light for Gear Down.  Even when pushing the test button in I am getting just very faint/dim indication.  The gear is actually down and the football on the floor is lit and showing gear down properly.  I know the annunciator is a "convenience" indication for the gear, but I'd like it working properly.  

Any suggestions on this one?  I would have thought it was a wiring issue or something to do with the switch in that triggers the indicator IF the test button didn't also show a really dim indication.  And that friends is the issue--its so dim you cannot see if in daylight flight conditions.

That's because you recently replaced all of your incandescent lights (landing, taxi, nav) with LED lights. That would make it do what you're describing. You'll need a relay somewhere in that circuit. There's a thread on here somewhere talking about that and I think @PT20J commented about this.

[PT20J]

@LANCECASPER is correct. The annunciator panel runs a ground return for the gear light through the nav light circuit to make the gear light bright when the  nav lights are off and dim when they are on. It works because an incandescent filament has a low resistance when the lights are off. But LEDs don’t work that way. Someone posted a circuit using a relay to fix this but I don't remember who. It was. But any competent avionics shop should be able to figure it out. The annunciator circuitry is described in the M20J service manual and probably the M20TN manual also.

Skip

[carusoam]

Let’s invite the LED guy…. @OSUAV8TER

He has a memory for all things related to LED upgrades…  (annunciator panel dim gear down light)

Best regards,

-a-

[M20TN_Driver]

Very Interesting.  You are 100% correct.  Yes I did recently swap all lights out for LED.  I guess I need to go back to Gallagher Aviation that sold me the LEDs for the acclaim--never mentioned that this would need to be addressed.  Atleast it is a known thing so I am not chasing ghosts!  Thank you all so much for the help.

[carusoam]

16 hours ago, M20TN_Driver said:

Very Interesting.  You are 100% correct.  Yes I did recently swap all lights out for LED.  I guess I need to go back to Gallagher Aviation that sold me the LEDs for the acclaim--never mentioned that this would need to be addressed.  Atleast it is a known thing so I am not chasing ghosts!  Thank you all so much for the help.

Mr. Gallagher is our LED guy… @OSUAV8TER

He likes to be knowledgable with all things related to his product line…

Best regards,

-a-

[OSUAV8TER]

Good morning! 

Just seeing this now. I was not aware that this is an issue or will result in an issue but I'm very interested to see what other owners have done to eliminate this issue. I know on older model Bonanzas, because I have one, now that I leave the Nav lights on it dims the gear up and down lights because of a switch that dims the bulbs. This will get permanently fixed by the avionics shop soon. I'm here to help, however I can and am now following the topic. 

James

[LANCECASPER]

23 hours ago, M20TN_Driver said:

Very Interesting.  You are 100% correct.  Yes I did recently swap all lights out for LED.  I guess I need to go back to Gallagher Aviation that sold me the LEDs for the acclaim--never mentioned that this would need to be addressed.  Atleast it is a known thing so I am not chasing ghosts!  Thank you all so much for the help.

I have a 2008 Acclaim Type S and I put in the LED nav/strobes etc this summer, but intentionally did not change out the landing and taxi lights since the HID lights that the Mooney factory put in are low current draw, compared to incandescent,  very long life and extremely bright.

My "Gear Down" annunciator does not dim beyond what it should. Here's a quick video: https://www.dropbox.com/s/rno0asb90a85i3a/gear down indicator.MOV?dl=0

[M20TN_Driver]

Very Interesting.  You are 100% correct.  Yes I did recently swap all lights out for LED.  I guess I need to go back to Gallagher Aviation that sold me the LEDs for the acclaim--never mentioned that this would need to be addressed.  Atleast it is a known thing so I am not chasing ghosts!  Thank you all so much for the help.

[M20TN_Driver]

So, I have gone back and reviewed all of the threads and even called Gallagher Aviation as that is where I purchased the LEDs from.  Although, it doesn't appear that anyone contacted Whelen or Mooney about the issue. I was a little bummed out because the LEDs are advertised as "drop in" replacements and what I have come to understand is that is mostly true ;-)

I have been in touch with Whelen and am working directly with them as their folks seem to have no knowledge that this was even an issue for Mooney aircraft.  They are currently running a discussion with Mooney tech support and will be back to me with a recommended approach.  My guess is that they are going to recommend the same relay approach that others have suggested, but hopefully with some documentation and step-by-step that I can give to a local shop.

I'll keep everyone posted.

[Pinecone]

https://mooneyspace.com/topic/33825-new-installed-whelen-led-nav-strobe/

[N231BN]

I have mentioned this in previous threads, but I like to have independent control of the light circuits. The easiest method is to remove the annunciator wire from the nav light switch and connect it to ground through a simple toggle switch labeled DAY/NIGHT. Ground is bright, open is dim.

I like my gear lights to be bright.

[Pinecone]

That is a pretty simple solution.

[M20TN_Driver]

Agreed that is the simplest solution.  I was looking for (hopefully) Whelen to come out with a tech note or something for Mooney owners that offers a two pager with a diagram on what/how they and Mooney believe it should be solved.  I am pretty sure a simple relay will be the answer.  

When I spoke to Whelen they confirmed that this was also their desire--a small write up on recommended approach to fix the issue.

[atpdave]

When I converted my Ovation2 to LED nav lights I left the A508-28 incandescent bulbs in the aft tip positions so the dimming function would still work.  I think the cold resistance of those 2 bulbs in parallel is less than 2 ohms.  The GEAR DOWN annunciator brightens/dims properly.  If I need a replacement bulb and can't get one I would probably install a relay, and I would also like to know what kind WAT/Mooney would specify.

[carusoam]

10 hours ago, M20TN_Driver said:

Agreed that is the simplest solution.  I was looking for (hopefully) Whelen to come out with a tech note or something for Mooney owners that offers a two pager with a diagram on what/how they and Mooney believe it should be solved.  I am pretty sure a simple relay will be the answer.  

When I spoke to Whelen they confirmed that this was also their desire--a small write up on recommended approach to fix the issue.

Note for @OSUAV8TER…

-a-

[M20TN_Driver]

On 10/18/2022 at 7:15 AM, LANCECASPER said:

I have a 2008 Acclaim Type S and I put in the LED nav/strobes etc this summer, but intentionally did not change out the landing and taxi lights since the HID lights that the Mooney factory put in are low current draw, compared to incandescent,  very long life and extremely bright.

My "Gear Down" annunciator does not dim beyond what it should. Here's a quick video: https://www.dropbox.com/s/rno0asb90a85i3a/gear down indicator.MOV?dl=0

If I knew then what I know now, I would never have replaced the landing/taxi HID lights. I would have just done the wingtip strobes and the tail strobe. Would have saved me a bunch of headache.