M20E gear indicator in floor - How to replace bulb?

[DoctorJay69]

Ok, guys.  I know there is a bulb in there somewhere to let you see the lines aligned indicating the gear is safely down. I can't seem to find the bulb, and, resultant to that, don't know what bulb goes in there. I'd like to have the bulb in hand ready to swap out once I find out where it is!!!

instructions would be much appreciated and pics would be even better.  Thanks in advance! This website is awesome!!!!!

Edited November 27, 2016 by DoctorJay69

[TTaylor]

In general it is accessed from the underside by removing the belly panels beneath it. You can remove the seats and all the plastic in the center but much harder that way.  The parts manual calls out a specific bulb, when I went to replace one on our 75F it did not match.  The shop elves ended up using a high brightness LED with a resistor epoxied into the base of the old bulb. it is much brighter than the standard bulb with less heat.

Here is the old thread:

Search Google for Mooneyspace gear bulb.   I can't paste the link here for some reason.

[TTaylor]

 

[carusoam]

Often the original bulb was 24V in a 12V system...   kind of dim that way, but worked well...

Best regards,

-a-

[DonMuncy]

On my K, kind of dim was an gross understatement. I felt like I had to get a flashlight to see if it was on. Changing to a 12 volt bulb worked wonders.

[Guest]

You'll have to remove a few belly panels to gain access to the bulb holder, then you'll need a 5/16" ignition wrench to remove the two sided retaining nut which is at the glass end of the bulb.  The bulb is normally a GE327 (28vdc) in 14vdc airplanes, but installing a GE330 is brighter.

Clarence

[Ragsf15e]

Help… where do i put the wrench and turn to take out the tiny light?

[PT20J]

That looks different than mine. But I notice that the plastic part where the wire comes out is square. Does it unscrew from the housing?

[Ragsf15e]

4 minutes ago, PT20J said:

That looks different than mine. But I notice that the plastic part where the wire comes out is square. Does it unscrew from the housing?

Possibly.  I tried a gentle turn and got nowhere but maybe it needs more.  I’m try to be careful.

I might have access from the top too so I’m going to take those screws off tomorrow and look.

@EricJ ?

@N201MKTurbo?

[EricJ]

Just now, Ragsf15e said:

Possibly.  I tried a gentle turn and got nowhere but maybe it needs more.  I’m try to be careful.

I might have access from the top too so I’m going to take those screws off tomorrow and look.

@EricJ ?

I don't remember, either, and I'm not positive that that looks like mine did.    I do remember being disappointed that I had made mine a lot harder than it needed to be.

 

[EricJ]

13 minutes ago, Ragsf15e said:

Possibly.  I tried a gentle turn and got nowhere but maybe it needs more.  I’m try to be careful.

I might have access from the top too so I’m going to take those screws off tomorrow and look.

@EricJ ?

@N201MKTurbo?

Mine looked quite a bit different.    iirc mine had a nut on the other side of this that retained the fixture, but it came out reasonably easy.   Yours looks different, tho. 

Edit:   FWIW, it looks like if you take torque off that small hex nut, it'll make the one on the other side finger loose and may remove easily, then the fixture would come out...I *think*.

[Guest]

3 hours ago, Ragsf15e said:

Help… where do i put the wrench and turn to take out the tiny light?

The black connector seems different than most, use a mirror to look on the light bulb side and see if the retainer bezel is there.

[carusoam]

That square shape seems to be designed in for a reason…. But, +1 on torque caution…

Plastic can get brittle over the years…

just enough to break the sticktion, not the part… 

Best regards,

-a-

[Ragsf15e]

On 1/23/2023 at 3:07 PM, PT20J said:

That looks different than mine. But I notice that the plastic part where the wire comes out is square. Does it unscrew from the housing?

So Skip and Carusum were right! The black plastic end cap screwed off and the whole socket and bulb dropped downward into easy reach.  I celebrated (too early), went and grabbed my new bulb and found it slight bigger than the existing one and too big to fit in the socket!  Crap, that new socket has a GE336 in it instead of the GE330 we normally use.  So I have a $25 bulb on the way from AeroLeds… $5 bulb and $20 expedited shipping.

[PT20J]

1 hour ago, Ragsf15e said:

So Skip and Carusum were right! The black plastic end cap screwed off and the whole socket and bulb dropped downward into easy reach.  I celebrated (too early), went and grabbed my new bulb and found it slight bigger than the existing one and too big to fit in the socket!  Crap, that new socket has a GE336 in it instead of the GE330 we normally use.  So I have a $25 bulb on the way from AeroLeds… $5 bulb and $20 expedited shipping.

Well, that's a new one: I've never seen a bulb holder like that one, or heard of a 336 bulb.

Reminds me of my 1978 M20J. Soon after I bought it the flap/trim position indicator bulb burned out. It wasn't replaceable from the front of the console like the later models. To get to it, I had to drill out pop rivets to remove the side panel. Then an aileron push-pull tube was in the way. Disconnecting the rod end still didn't get it far enough out of the way, so I had to go underneath and remove a belly skin and disconnect the other end. Then I could get to the bulb which I removed and took to the avionics shop on the field. It was some kind of weird bulb (maybe a 336?) that they didn't have and had to order, so I had to put the whole thing back together to fly it and then repeat to install the bulb when it arrived. That's when I learned something about the way Mooneys are built.

Skip

[Ragsf15e]

1 hour ago, PT20J said:

Well, that's a new one: I've never seen a bulb holder like that one, or heard of a 336 bulb.

Reminds me of my 1978 M20J. Soon after I bought it the flap/trim position indicator bulb burned out. It wasn't replaceable from the front of the console like the later models. To get to it, I had to drill out pop rivets to remove the side panel. Then an aileron push-pull tube was in the way. Disconnecting the rod end still didn't get it far enough out of the way, so I had to go underneath and remove a belly skin and disconnect the other end. Then I could get to the bulb which I removed and took to the avionics shop on the field. It was some kind of weird bulb (maybe a 336?) that they didn't have and had to order, so I had to put the whole thing back together to fly it and then repeat to install the bulb when it arrived. That's when I learned something about the way Mooneys are built.

Skip

That sounds about right.  I was about to go in from the top which seemed to require an octopus with really long arms as an assistant since there were screws in the cabin with free nuts in the belly.  I went back for one more look under and got lucky.  The 336 is almost identical but slightly smaller and they are use for avionics too.  The base is just a little different…

[Ragsf15e]

Success!!

it didn’t go without a fight, however. I got the correct bulb for the plastic socket, but when I put it in, the wire fell out the back of the socket. The solder broke up in the socket. So I handed the tiny plastic and metal socket to my IA and said, what do we do? he said, take it apart and see if we can fix it. Some very small soldering and gentle, disassembly and reassembly, and it’s fixed! 

[Raymond J1]

When we tell you about "electricity fairy"...
Well with a Mooney, you believe it !

[EricJ]

Nice!   Mine was a night-and-day change and went from being extremely difficult to see, even with a functioning incandescent lamp, to be being bright and easy to see.   Now I can actually do floor indicator checks before landing.

 

[Ragsf15e]

36 minutes ago, EricJ said:

Nice!   Mine was a night-and-day change and went from being extremely difficult to see, even with a functioning incandescent lamp, to be being bright and easy to see.   Now I can actually do floor indicator checks before landing.

 

Yeah, my mechanic was unimpressed, but I was super happy to see that green light!  It doesn’t come on until the gear is down AND it lets you see the indicator!

[Z00mie]

Necro thread an all, but,

when is this light supposed to illuminate? Is it tied to the instrument reostat? Or, is it on all the time? Mine isn't working so not sure what triggers it in a 1966 M20E.

[Ragsf15e]

1 hour ago, Z00mie said:

Necro thread an all, but,

when is this light supposed to illuminate? Is it tied to the instrument reostat? Or, is it on all the time? Mine isn't working so not sure what triggers it in a 1966 M20E.

Mine is on with the gear down and master on.  Off with gear up.  It’s not connected to the instrument lights.  The okder bulbs are dim or burnt out. 

[Z00mie]

Awesome! Thanks RagsF15E!