Electrical issues…67 M20F

[HwkIFan]

Looking for some info on the expected voltage at the landing gear indicator switch on a 67 Mooney M20F with a Johnson bar. Currently, with master on, the gear down light is not illuminating. Haven’t jacked the plane to check the gear up indication as I’m working to acquire some jacks. Am wondering what voltage I should see across the switch. 

[N201MKTurbo]

If you brace yourself, you can unlatch the Johnson bar and pull it out an inch or so so you can get to the micro switch to check its function.

Just be careful. I have done this many times. The wheels are firmly stuck to the ground, and would probably be hard to actually retract, but I wouldn’t tempt fate. 

[ShuRugal]

That switch should have 12 on it.

In one position, it feeds that voltage to the "gear down" light, and in the other it feeds the "gear not down" light, as well as sending power the throttle switch for the "your great isn't down, dummy" horn.

Sent from my Pixel 3a using Tapatalk

[ShuRugal]

If you brace yourself, you can unlatch the Johnson bar and pull it out an inch or so so you can get to the micro switch to check its function.
Just be careful. I have done this many times. The wheels are firmly stuck to the ground, and would probably be hard to actually retract, but I wouldn’t tempt fate. 

I know an IA who had a Mooney he was under fall on him when he said "put the flaps down" and the fella in the cockpit pulled the wrong bar, so it's definitely possible.

Sent from my Pixel 3a using Tapatalk

[N201MKTurbo]

2 minutes ago, ShuRugal said:

I know an IA who had a Mooney he was under fall on him when he said "put the flaps down" and the fella in the cockpit pulled the wrong bar, so it's definitely possible.

Sent from my Pixel 3a using Tapatalk
 

That seems more likely with electric gear and flaps.

[ShuRugal]

That seems more likely with electric gear and flaps.

You'd think so, but this guy did it with the bar.

Sent from my Pixel 3a using Tapatalk

[N201MKTurbo]

2 minutes ago, ShuRugal said:

You'd think so, but this guy did it with the bar.

Sent from my Pixel 3a using Tapatalk
 

I guess he thought it was an old Piper or Cessna.

[carusoam]

wait a sec…
 

in the words of the famous pilot gru… Light Bullllb…. 

The system is ultra simple…

Has voltage or doesn’t…

 

Where it gets tricky…

Young bucks with new 2them planes aren’t always familiar with their iris dimming controlled lights…

Twist Open the iris to see if the light shines through… 

If not familiar with the mechanical iris in the lights, now would not be the best time to unlock the mechanical landing gear… 

PP thoughts only, not a mechanic…

Best regards,

-a-

[HwkIFan]

appreciate the input...problem is this appears to be intermittent.  the lights are LEDs and confirmed to work. I thought it might be the switch but occasionally, the LED (green of course) is bright, sometimes dim, most times not lit. This is just one issue...panel lights (no bulb comment req'd...they also work) also intermittent. If anyone knows a good A&P with electrical skills (not all A&Ps fit this skillset) in the SA TX area, sure would appreciate a recommendation. Need someone willing to tome to my hangar.

[N201MKTurbo]

6 minutes ago, HwkIFan said:

appreciate the input...problem is this appears to be intermittent.  the lights are LEDs and confirmed to work. I thought it might be the switch but occasionally, the LED (green of course) is bright, sometimes dim, most times not lit. This is just one issue...panel lights (no bulb comment req'd...they also work) also intermittent. If anyone knows a good A&P with electrical skills (not all A&Ps fit this skillset) in the SA TX area, sure would appreciate a recommendation. Need someone willing to tome to my hangar.

So, what year is your F? The later models had a circuit that dims the gear lights when the nav lights are turned on. It does this to reduce the brightness at night.

[Ragsf15e]

1 hour ago, N201MKTurbo said:

So, what year is your F? The later models had a circuit that dims the gear lights when the nav lights are turned on. It does this to reduce the brightness at night.

And in addition to this, LEDs are not good on our ancient dimming circuits.  Often they just don’t work.  The dimmer for most of my panel is overhead the copilot on a ‘68F.  However, my gear lights have the individual “iris” dimmers.

Edited October 11, 2021 by Ragsf15e

[Shiny moose]

On a 67F it is not a complicated system. 

 

[1964-M20E]

20 hours ago, N201MKTurbo said:

If you brace yourself, you can unlatch the Johnson bar and pull it out an inch or so so you can get to the micro switch to check its function.

Just be careful. I have done this many times. The wheels are firmly stuck to the ground, and would probably be hard to actually retract, but I wouldn’t tempt fate. 

Only if the plane is on jacks, but to each his own.

[N201MKTurbo]

27 minutes ago, 1964-M20E said:

Only if the plane is on jacks, but to each his own.

If it is on jacks, you don't have to brace yourself or be careful, you can do whatever you want.

[carusoam]

Hey…. Wait a minute… again….

Is this LED light on a standard old dimming circuit?

Is the dimmer being touched at any time, or is it left on full bright?

 

Some LEDs don’t work very well with the old standard dimmers…

There are specialized dimmers for that…

There are also ways of including an incandescent bulb in the circuit to aid in the dimming…

 

PP thoughts only, not a mechanic…

Best regards,

-a-

[Shiny moose]

Stated he has a 67F, unless changes have been made, no dimmer on the gear lights except the iris. How about a picture for all of us to see. 

[Ragsf15e]

4 hours ago, Shiny moose said:

Stated he has a 67F, unless changes have been made, no dimmer on the gear lights except the iris. How about a picture for all of us to see. 

True, but they also don’t have LED gear lights as standard.  Some changes have been made.  I wonder if there's a compatible LED that can fit in yhe iris socket or if that changed as well?

[N201MKTurbo]

I wonder why everybody wants to change out their landing gear indicator lights to LEDs. I had a 67 M20F for 19 years. I flew it for 4500 hours. I never replaced those lights, they kept on going. Is that not reliable enough? 

Edited October 12, 2021 by N201MKTurbo

[Shiny moose]

10 minutes ago, N201MKTurbo said:

I wonder why everybody wants to change out their landing gear indicator lights to LEDs. I had a 67 M20F for 19 years. I flew it for 4500 hours. I never replaced those lights, they kept on going. Is that not reliable enough? 

I totally agree with you

[Ragsf15e]

33 minutes ago, N201MKTurbo said:

I wonder why everybody wants to change out their landing gear indicator lights to LEDs. I had a 67 M20F for 19 years. I flew it for 4500 hours. I never replaced those lights, they kept on going. Is that not reliable enough? 

Definitely.  I have LEDs on all the “outside” lights but the gear lights are just fine.  And there’s a good backup gear indicator on the floor.

[ShuRugal]

True, but they also don’t have LED gear lights as standard.  Some changes have been made.  I wonder if there's a compatible LED that can fit in yhe iris socket or if that changed as well?

Yes, Spruce has some. They also have LED indicator fixtures which are more or less identical to the existing iris-dimmed indicators, but have non-removable bulbs, but I didn't see the point of going for those.

Sent from my Pixel 3a using Tapatalk

[N201MKTurbo]

2 minutes ago, Ragsf15e said:

Definitely.  I have LEDs on all the “outside” lights but the gear lights are just fine.  And there’s a good backup gear indicator on the floor.

Landing lights are a good thing to change. But even the nav lights are a hard sell for me. I’m going on 40 years of Mooney ownership (damn I’m getting old) and I’ve only changed two nav light bulbs. I think I paid $12 for the last one. Doesn’t make me want to go out and spend 1+AMUs for LEDs. What problem is this solving?

[Shadrach]

On 10/10/2021 at 9:16 PM, HwkIFan said:

appreciate the input...problem is this appears to be intermittent.  the lights are LEDs and confirmed to work. I thought it might be the switch but occasionally, the LED (green of course) is bright, sometimes dim, most times not lit. This is just one issue...panel lights (no bulb comment req'd...they also work) also intermittent. If anyone knows a good A&P with electrical skills (not all A&Ps fit this skillset) in the SA TX area, sure would appreciate a recommendation. Need someone willing to tome to my hangar.

Reads like an Intermittent ground. I’ve had the panel lights manefest the same issue on both sides and the panel. It was alway a ground issue. Vibrations can further complicate electrical issues by either making the problem go away  or causing it.

[Ragsf15e]

2 hours ago, N201MKTurbo said:

Landing lights are a good thing to change. But even the nav lights are a hard sell for me. I’m going on 40 years of Mooney ownership (damn I’m getting old) and I’ve only changed two nav light bulbs. I think I paid $12 for the last one. Doesn’t make me want to go out and spend 1+AMUs for LEDs. What problem is this solving?

Fair enough.  Luckily the previous owner of mine did it.  Getting strobes and removing the coffee can beacon has to be good for 1 knot, no?  I’ve only had mine for 7 years but I sent back the tail led because it wasn’t working (replaced for free) and one wing nav/strobe filled with water (still working) which was also replaced for free.