Landing Light Switch on 1979 M20J

[robert38606]

My landing light switch seems to be broken.  It will turn on momentarily then turn off (and sometimes flash like a strobe).  I believe I must have bad switch.   I THINK the switch I need is on Lasar's site at the link below as part 930023-235A, but it's sold out (and has an enormous price even if it were available).

What's everyone doing when this happens?  It doesn't look like they have any in stock that are the same even if it were a beacon switch instead of a landing light switch.

https://lasar.com/switches/rocker-switch-landing-light-circuit-breaker-930023-235a

[EricJ]

That switch is a breaker switch.   If it won't stay on check the landing light wiring inside the cowl.   It may be that you have a short circuit that can be repaired.   Once in a while the wiring gets up against the exhaust and gets melted and shorts.   When that happens the switch won't stay on.

 

[robert38606]

17 minutes ago, EricJ said:

That switch is a breaker switch.   If it won't stay on check the landing light wiring inside the cowl.   It may be that you have a short circuit that can be repaired.   Once in a while the wiring gets up against the exhaust and gets melted and shorts.   When that happens the switch won't stay on.

 

I'll check that out, but the switch itself doesn't really click into place well when it's switched on either. it'll some times flop back in the middle between off and on

[N201MKTurbo]

If your switch cover is in good shape, you can get that breaker switch with a plain white cover for a lot less money. They are usually available. Just carefully snap off your cover and snap it on the new breaker switch.

[robert38606]

Just now, N201MKTurbo said:

If your switch cover is in good shape, you can get that breaker switch with a plain white cover for a lot less money. They are usually available. Just carefully snap off your cover and snap it on the new breaker switch.

Where might I find a generic circuit breaker switch?  I've been searching around for a couple hours but must not have found the correct one.  Does it use some other part number?  Air Power has some new at 318

[N201MKTurbo]

Yes, it is a 20TC2-BA-15

You should get an LED landing light. You will never have a switch problem again.

[robert38606]

3 minutes ago, N201MKTurbo said:

Yes, it is a 20TC2-BA-15

You should get an LED landing light. You will never have a switch problem again.

Well, thing is, I already have whelen led lights.  I bought the plane two months ago though so maybe this problem was there even before the avionics shop put the led lights in

[N201MKTurbo]

3 minutes ago, robert38606 said:

Well, thing is, I already have whelen led lights.  I bought the plane two months ago though so maybe this problem was there even before the avionics shop put the led lights in

If it is tripping with an LED, I would follow Eric’s advice and check the wiring. 

[robert38606]

18 minutes ago, N201MKTurbo said:

If it is tripping with an LED, I would follow Eric’s advice and check the wiring. 

Will do

[A64Pilot]

I don’t think it’s tripping, when one trips it stays off, not coming on and off flashing. I think he has a bad switch, but checking wiring can’t hurt 

[carusoam]

On 3/13/2022 at 6:24 PM, robert38606 said:

My landing light switch seems to be broken.  It will turn on momentarily then turn off (and sometimes flash like a strobe).  I believe I must have bad switch.   I THINK the switch I need is on Lasar's site at the link below as part 930023-235A, but it's sold out (and has an enormous price even if it were available).

What's everyone doing when this happens?  It doesn't look like they have any in stock that are the same even if it were a beacon switch instead of a landing light switch.

https://lasar.com/switches/rocker-switch-landing-light-circuit-breaker-930023-235a

Robert,

You have defined the classic failure of a worn circuit breaker switch…

They are mechanical devices that wear at an accelerated pace… 

Each time the switch gets operated a tiny spark ejects a tiny atom of metal from the surface….

Over the years… the high current ones wear….

 

Swapping a new one in is a bit challenging… it helps if you have good access behind the panel…

A piece of metal called a bus bar connects it to a family of other CBswitches… taking the bus bar off is part of the job…

 

The hint that it wore out…the click is gone.

The click gets in the way of the switch going over center…

When the click is no longer there, the switch goes over center on its own… or goes over center more easily as it warms up…

 

Get new switch… compare the feel of what a new click is like….  
 

New LEDs to go with the new switch… will probably allow the new switch to last forever…

New CB switches are available through aircraftspruce… pay attention while ordering…. They usually come with one cap that is printed… the name on the switch ldg lite will have a -part number for it…

A company called Sensata probably makes the switch, and has a nice technical page for it…. Mooneys use a couple of different versions of it… so make sure you get the right one…

Each switch gets one cap… they won’t allow you to get a second one later… for some reason…
 

PP thoughts only, not a mechanic…

Best regards,

-a-

[rgpilot]

I have a new switch with Mooney packaging but it looks slightly different than the Laser part. Marking is the same on face.

Text me and I will send you pictures.  631-804-9677

Part No. 930023-215

Edited March 15, 2022 by rgpilot

[AH-1 Cobra Pilot]

On 3/13/2022 at 5:24 PM, robert38606 said:

My landing light switch seems to be broken.  It will turn on momentarily then turn off (and sometimes flash like a strobe).  I believe I must have bad switch.   I THINK the switch I need is on Lasar's site at the link below as part 930023-235A, but it's sold out (and has an enormous price even if it were available).

What's everyone doing when this happens?

I have had similar problems with a switch or two.  The switch would not stay ON, unless held in place.  If that is what yours are doing, all they need is to fix the pin that serves as a pivot point. 

As they wear, the pins slide out to the side, and the switch has too much play, so that it will not remain latched in the ON position.  The pins are metal, 1mm or so in diameter and 2-3mm long.  (Those measurements are only from memory and VERY approximate.)  If you can find the pin, it can be put back into position, although it may still work its way out.  I bought replacements on Amazon, (https://www.amazon.com/gp/product/B000N64BN8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1).  (Funny, they were about half as much when I ordered them.  Inflation.)  Unfortunately, I do not remember if they fit perfectly as is, or needed some scraping with an razor blade.  Mine have not been a problem since.

[jezzie]

I may have one from a salvaged 78 M20J 

message me if you are interested.

 

[N444JJ]

We have a 1993 M20J.  The landing light toggle switch (left one is frozen in the off position, right one works fine).  It was working fine.  Don’t want to force it.

1. Any suggestions of what may be wrong.

2. I see some people had switches available back in March.  Does anyone still have one?  

3. Anyone have a part number? Or suggestion where to buy?  Aircraft Spruce? Sensata? Assuming Lasar does not have.

Thanks

Kim

[joepilotmooney]

I am now having an issue with my landing light switch. The rocker switch breaker has popped three times, and turns off. When the switch is turned on, all the engine gauges jump up. I've seen on the site that that the gauge panel contacts may need to be cleaned, as there is some short back there. Or, is it maybe I have a bad switch? I think at annual in a few months I will deal with this. Any other suggestions?

[N201MKTurbo]

1 hour ago, joepilotmooney said:

I am now having an issue with my landing light switch. The rocker switch breaker has popped three times, and turns off. When the switch is turned on, all the engine gauges jump up. I've seen on the site that that the gauge panel contacts may need to be cleaned, as there is some short back there. Or, is it maybe I have a bad switch? I think at annual in a few months I will deal with this. Any other suggestions?

It sounds like your landing light is shorted. Unhook the positive wire from the landing light and see if it still does this. If it does, it is a shorted wire. if not, it is a shorted landing light.

The jumping gauges is indicative of a short, when you turn on the landing light, it draws so much current that it drops the bus voltage until the breaker trips.

[William A]

I’m having this issue with my landing light rocker switch. No voltage coming from my breaker switch on my 1984 m20J. Lasar does not have any replacement and still waiting for sensata to respond to my email about a possible replacement.

[LANCECASPER]

12 minutes ago, William A said:

I’m having this issue with my landing light rocker switch. No voltage coming from my breaker switch on my 1984 m20J. Lasar does not have any replacement and still waiting for sensata to respond to my email about a possible replacement.

Install another identical switch with the same specs and just put the cap from your old one on the replaced switch

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p4432023.m570.l1313&_nkw=mooney+switch&_sacat=0.

[carusoam]

On 11/2/2024 at 10:43 AM, William A said:

I’m having this issue with my landing light rocker switch. No voltage coming from my breaker switch on my 1984 m20J. Lasar does not have any replacement and still waiting for sensata to respond to my email about a possible replacement.

Sensata doesn’t sell direct to customers… because they suck…  (plus they won’t sell just the printed switch caps)

I use aircraft spruce… they may have them  in stock, or can get from Sensata quite quickly…

+1 for holding onto your existing switch caps… they snap on and off an oversized metal body…

Landing lights of the original kind…(not LED)

use a lot of electricity and generate a tiny spark each time you turn them on… this tiny spark knocks a micro piece of metal off the contact surface…. After years of operation, the CB switch loses its over center nature…

the click gets softer and softer over time, as does its ability to resist tripping.

 

PP thoughts only, not a mechanic…

best regards,

-a-

[William A]

1 hour ago, carusoam said:

Sensata doesn’t sell direct to customers… because they suck…  (plus they won’t sell just the printed switch caps)

I use aircraft spruce… they may have them  in stock, or can get from Sensata quite quickly…

+1 for holding onto your existing switch caps… they snap on and off an oversized metal body…

Landing lights of the original kind…(not LED)

use a lot of electricity and generate a tiny spark each time you turn them on… this tiny spark knocks a micro piece of metal off the contact surface…. After years of operation, the CB switch loses its over center nature…

the click gets softer and softer over time, as does its ability to resist tripping.

 

PP thoughts only, not a mechanic…

best regards,

-a-

I changed my led light out about 150 hours ago (1.5 yrs ago) and it had an led bulb already so crossing my fingers it’s nothing more than the switch but we will see.

I haven’t found any generic switches on aircraft spruce website but maybe I should call them and ask about them ordering me one from sensata.

i did find someone on eBay that has a used one from a 1975 Mooney but I would prefer new of course.

[201Mooniac]

15 hours ago, William A said:

I changed my led light out about 150 hours ago (1.5 yrs ago) and it had an led bulb already so crossing my fingers it’s nothing more than the switch but we will see.

I haven’t found any generic switches on aircraft spruce website but maybe I should call them and ask about them ordering me one from sensata.

i did find someone on eBay that has a used one from a 1975 Mooney but I would prefer new of course.

I might have one from my 80 M20J, I replaced all the switched about 16 years ago when I redid the panel and held on to all the old ones.  DM me if you'd like me to check for it.

[William A]

On 11/4/2024 at 6:44 PM, carusoam said:

Sensata doesn’t sell direct to customers… because they suck…  (plus they won’t sell just the printed switch caps)

I use aircraft spruce… they may have them  in stock, or can get from Sensata quite quickly…

+1 for holding onto your existing switch caps… they snap on and off an oversized metal body…

Landing lights of the original kind…(not LED)

use a lot of electricity and generate a tiny spark each time you turn them on… this tiny spark knocks a micro piece of metal off the contact surface…. After years of operation, the CB switch loses its over center nature…

the click gets softer and softer over time, as does its ability to resist tripping.

 

PP thoughts only, not a mechanic…

best regards,

-a-

I might have found a new switch from sensata however I don’t have my switch out of the plane yet and they need the measurements to make sure it will fit especially the distance between the mounting holes. If anyone has these measurements can you please share?

here is the possible new replacement…

 

[carusoam]

On 11/7/2024 at 12:17 PM, William A said:

I might have found a new switch from sensata however I don’t have my switch out of the plane yet and they need the measurements to make sure it will fit especially the distance between the mounting holes. If anyone has these measurements can you please share?

here is the possible new replacement…

 

Dimensions for the switch are available from Sensata website, drawing…

the chance of any matching switch not fitting… is slim to none…

they have all been the same basic shape for several decades…

PP thoughts only…

Best regards,

-a-

 

inviting @jkarch 

[William A]

It looks so close but I think the old one looks like 1 5/8 or 1.62 inches so I’m second guessing myself! If I am reading the drawing correctly I think im seeing 1.82 or 1.79 inches middle of both holes on the new one from sensata…

 

Edited November 13, 2024 by William A