Cessna 182P Tail Beacon Does Not Work When Engine Running

[Sinistar]

So I have noticed that the tail beacon does not work...only when the engine is running. Any ideas of what might be wrong?

Quirk: On this plane, the Master + Beacon + Radio's Power need to be on for the tail beacon to work. But once the engine is running, the tail beacon no longer works. All other lights work properly whether engine running or not. And all other lights (including the white strobe on top) work whether the radios are on or not. The white strobe and the tail beacon are split switches and even if I turn the white strobe off the tail light will not work...unless the engine is not running.

Have any of you experienced this or have any ideas of what might be going on?

Clearly it is getting power and that flasher unit back by the tail must be working to some degree. Obviously the bulb is working. I guess one thing I don't know is if the engine RPM were higher, perhaps it might work then. Seems like it should just always work?

 

[coloradobluesky]

Probably a bad ground or some other flaky, intermittant conection.

 

[denverpilot]

Test bus voltage engine running and not. Make sure in spec.

Test voltage delivered to beacon power supply is in spec and make sure wiring to the tail doesn't have a problem.

Disconnect tail beacon and drive it with a good variable D.C. voltage power supply directly and make sure it works properly in that configuration.

That's where I'd start.

 

[455 Bravo Uniform]

Is there a contractor in 182Ps that opens or closes once the engine starts? Related to the alternator field? I need to go back to my POH and Service Manual to check. Maybe someone rewired the beacon and tapped into that line by mistake. Longshot. I'd start with the two posts above first.

 

[denverpilot]

Is there a contractor in 182Ps that opens or closes once the engine starts? Related to the alternator field? I need to go back to my POH and Service Manual to check. Maybe someone rewired the beacon and tapped into that line by mistake. Longshot. I'd start with the two posts above first.

The voltage regulator in most Cessnas handles the duties of energizing the field and also providing the monitor light for "High Voltage" (which is actually an "anything failed" light for High/Low and no Alternator output) into the cockpit which is the only wire that goes where someone could reach it to do something that silly, hopefully.

The originals were mechanical but most of those have been replaced by solid state versions over the years unless someone is a purist.

 

[455 Bravo Uniform]

Any chance that the plane was rewired, and the entire electronic bus power source bypassed, except the beacon, and for some reason when the plane starts, the external power source contactor goes to open (maybe wired wrong) and the only thing still connected to it is the beacon? Stupid stretch, I know.

 

[BrianNC]

So I have noticed that the tail beacon does not work...only when the engine is running.

So cut the engine off. Problem solved.



















Sorry. Somebody had to say it.

 

[denverpilot]

A 182 makes a decent 7:1 glider...

 

[Norman]

Any chance prop wash is blowing out the candle?

 

[GlennAB1]

Engine running creates significant enough vibration for loose connection resistance to increase...? Check for voltage without and with engine running.

 

[Sinistar]

Sorry it took awhile to get back to this thread. I now have a few good places to start looking. Thank you!

I don't there has been any major rewiring, but needing the avionics switch on can not be standard. It's as if they want to protect that flasher just like the want to protect the radios from the startup EMF spike?

Hey, I thought a Skylane glide ratio was even better than 8:1 ... still no glider though

It's crossed my mind to just replace it with a LED with its own buit in flasher...gosh knows what that costs!

 

[denverpilot]

Hey, I thought a Skylane glide ratio was even better than 8:1 ... still no glider though

Probably memorized wrong. I'm very conservative with my memorized glide ratios. If the book says it'll do better, great. I probably can't.

 

[Kurt Fisch]

Good morning everyone .... I realize this is a old post however I am having the exact same problem. What was the issue and the solution?

 

[benyflyguy]

@Sinistar took the hint and started flying gliders.

 

[Sinistar]

@Sinistar took the hint and started flying gliders.

Me in a glider

 

[Sinistar]

Good morning everyone .... I realize this is a old post however I am having the exact same problem. What was the issue and the solution?

I should have come back and updated this thread...my bad.

One day I decided to tinker with this a bit more. When tracing the wiring from the tail back to the panel I found where the flasher unit was located. Just had to remove the baggage cover. I noticed the flasher seemed to have 2 sides or ports or whatever it should be called. So I switched it to the other one and it now works when the plane is running.

Please note, I still need my radio master switch on.

When I was looking at the manual it seems this flasher is not the original. Sorry I dont have a picture right now the plane is about 30 miles away.

Hope this helps.

 

[Kurt Fisch]

@Sinistar took the hint and started flying gliders.

I should have come back and updated this thread...my bad.

One day I decided to tinker with this a bit more. When tracing the wiring from the tail back to the panel I found where the flasher unit was located. Just had to remove the baggage cover. I noticed the flasher seemed to have 2 sides or ports or whatever it should be called. So I switched it to the other one and it now works when the plane is running.

Please note, I still need my radio master switch on.

When I was looking at the manual it seems this flasher is not the original. Sorry I dont have a picture right now the plane is about 30 miles away.

Hope this helps.

I should have come back and updated this thread...my bad.

One day I decided to tinker with this a bit more. When tracing the wiring from the tail back to the panel I found where the flasher unit was located. Just had to remove the baggage cover. I noticed the flasher seemed to have 2 sides or ports or whatever it should be called. So I switched it to the other one and it now works when the plane is running.

Please note, I still need my radio master switch on.

When I was looking at the manual it seems this flasher is not the original. Sorry I dont have a picture right now the plane is about 30 miles away.

Hope this helps.

Good morning .... That did help, The flasher unit on my airplane (182L) is up in the top of the tail, mounted just under the beacon and has two outputs. I connected the beacon to the other output and it works perfect. Seems that there is a failed component in the flasher unit related to that output and the difference of system voltage when the motor is not running (12.4) and when the motor is running (13.9) causes that output to not work properly. However, that's just an assumption. If the issue returns I will replace the beacon with an LED unit.
Thanks for your reply it really helped.