Position light issue

[Desertdoc75]

I've noticed an issue with my rear nav / position light since I flew Moonship home. Anytime I add electrical load when the nav lights are on, they switch off. Yesterday I removed the rear lamp to get some part numbers (upgrading to LED) and noticed  the light shorts out when the bulb is manipulated. Now I've got to find the exact location of the issue. Anyone experience this before and have any wisdom of how to investigate and fix without ripping the entire line out?

 

 

[Desertdoc75]

Here's a short video........

IMG_1534.MOV

[Mooneymite]

Not very familiar with the tail light fixture, but if it shorts out when you manipulate the bulb, that's a great indication that the problem is at the fixture.....and that's good news.

 

[RLCarter]

looking at the video it looks like the light only comes when the housing is touched to the airframe, if this is the case that is normal as there is no ground wire to complete the circuit.

[DonMuncy]

 

Just now, RLCarter said:

looking at the video it looks like the light only comes when the housing is touched to the airframe, if this is the case that is normal as there is no ground wire to complete the circuit.

Agreed, when you put the lamp housing in contact with the plane, it completes the circuit (to ground) and comes on, as it should.

[Desertdoc75]

9 minutes ago, DonMuncy said:

 

Agreed, when you put the lamp housing in contact with the plane, it completes the circuit (to ground) and comes on, as it should.

I was wondering that aspect as well.

 

[N201MKTurbo]

If they are switching off by themselves, you probably have a weak breaker. Switching to LEDs will take care of it.

[DonMuncy]

8 minutes ago, N201MKTurbo said:

If they are switching off by themselves, you probably have a weak breaker. Switching to LEDs will take care of it.

I assumed from his original post that the light functioned fine until he took the fixture out.

[RLCarter]

2 hours ago, Desertdoc75 said:

I've noticed an issue with my rear nav / position light since I flew Moonship home. Anytime I add electrical load when the nav lights are on, they switch off. Yesterday I removed the rear lamp to get some part numbers (upgrading to LED) and noticed  the light shorts out when the bulb is manipulated. Now I've got to find the exact location of the issue. Anyone experience this before and have any wisdom of how to investigate and fix without ripping the entire line out?

if I'm reading this correct the Nav/Pos lights work fine until something else is turned on. If this the case what is the something else you are turning on and do they come back on when that something is turned off?

[Desertdoc75]

41 minutes ago, N201MKTurbo said:

If they are switching off by themselves, you probably have a weak breaker. Switching to LEDs will take care of it.

We shall soon see. Upgrading to LEDs in the next couple of weeks. 

[Desertdoc75]

Just now, RLCarter said:

if I'm reading this correct the Nav/Pos lights work fine until something else is turned on. If this the case what is the something else you are turning on and do they come back on when that something is turned off?

It's usually the fuel pump combined with the beacon. Upgrading to LEDs first and foremost and will re-evaluate from there. 

[RLCarter]

Just now, Desertdoc75 said:

It's usually the fuel pump combined with the beacon. Upgrading to LEDs first and foremost and will re-evaluate from there. 

is it tripping the Nav/Pos circuit breaker, or do they just go off?

[Desertdoc75]

It just goes off, but the switch doesn't immediately reset. Takes a minute or two. 

[carusoam]

Expect that the switch is a circuit breaker and switch combination.  The CB is temperature activated. An overload of amperage causes it to heat up.  When it hits a higher temp, the circuit opens up.

This type of CB has a tendency to wear out with time.  The click of the switch gets softer and softer as it wears.  The headlight CB is best known for wearing out after a few thousand hours of use...

the tail light wire runs along the bottom of the tail and has a tendency to get beat up and ruined while cleaning bird nest junk out of the tail.

PP thoughts only. Not a mechanic.

Best regrads,

-a-

Edited May 1, 2017 by carusoam

[Aviationinfo]

I have a standard Whelen nav/strobe combo on my '66 E.   I've been thinking about replacing the nav bulbs with LEDs, but it's not clear to me if Whelen makes a replacement LED nav bulb.   Which LEDs are you thinking of?

[Desertdoc75]

16 hours ago, Aviationinfo said:

I have a standard Whelen nav/strobe combo on my '66 E.   I've been thinking about replacing the nav bulbs with LEDs, but it's not clear to me if Whelen makes a replacement LED nav bulb.   Which LEDs are you thinking of?

Whelen. Orion for the tail, their generic LEDs for the wing tips, and the Parmetheus landing light.

[Desertdoc75]

17 hours ago, carusoam said:

Expect that the switch is a circuit breaker and switch combination.  The CB is temperature activated. An overload of amperage causes it to heat up.  When it hits a higher temp, the circuit opens up.

This type of CB has a tendency to wear out with time.  The click of the switch gets softer and softer as it wears.  The headlight CB is best known for wearing out after a few thousand hours of use...

the tail light wire runs along the bottom of the tail and has a tendency to get beat up and ruined while cleaning bird nest junk out of the tail.

PP thoughts only. Not a mechanic.

Best regrads,

-a-

Which is why I want to try the LED solution first. If that doesn't work, we'll replace the switch and start looking closer at the wiring.

[outermarker]

when going to LED's are you running new wiring to the switch or is it not necessary? I am in need of new strobe lenes if someone has some after they converted to LEDs.

 

[Marauder]

when going to LED's are you running new wiring to the switch or is it not necessary? I am in need of new strobe lenes if someone has some after they converted to LEDs.
 

Show me the lense you need. I upgraded to LEDs last Fall.


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[Marauder]

It's usually the fuel pump combined with the beacon. Upgrading to LEDs first and foremost and will re-evaluate from there. 

I purchased my LEDs at Oshkosh. They were running a special on them. Thanks to NotarPilot, I'm LED all around.

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[outermarker]

For some unknown reason (prior owner) the strobe lens is not glass and over time has yellowed, cracked and clouded over.

[carusoam]

Not so unknown...

UV light like sunlight has a way of degrading the plastic that it is made from.  It is probably polystyrene.  Some automotive headlights have the same problem with a more sturdy polymer.

Some MSers have replaced them.  There is  another thread with the details. I think he may have been building a simple mold to make parts.

Best regards,

-a-

Edited May 2, 2017 by carusoam

[Marauder]

For some unknown reason (prior owner) the strobe lens is not glass and over time has yellowed, cracked and clouded over.

Can't tell from your picture if mine are the same. Here is what mine look like. I will swing by the airport tomorrow and get a better picture of them.




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[outermarker]

Thanks, but it's the wrong type.