C150 landing light went out in flight fuse good

C

Christopher

Filing Flight Plan
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Jul 1, 2015
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Christopher
In mid flight the landing light stopped working - checked the fuse it was good. Landed checked it out no sign of anything wrong ( theres 2 lights ) it would seem strange they both stopped at the same time .. Thoughts? Any way to fix myself?

They stopped pulling amps from what I can see when I pull it on nothing changes ( does the same on ground and will not turn on)
 
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Christopher said:
In mid flight the landing light stopped working - checked the fuse it was good. Landed checked it out no sign of anything wrong ( theres 2 lights ) it would seem strange they both stopped at the same time .. Thoughts? Any way to fix myself?

They stopped pulling amps from what I can see when I pull it on nothing changes ( does the same on ground and will not turn on)
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Switch??:idea:
 
Broken ground wire. If it's the two cowling-mounted lights, the vibration is forever breaking the crimp terminals at the lights, and a broken ground terminal at the left-hand light will kill them both. Or the connector in the round wire near the firewall fell apart.

Dan
 
Dan Thomas said:
Broken ground wire. If it's the two cowling-mounted lights, the vibration is forever breaking the crimp terminals at the lights, and a broken ground terminal at the left-hand light will kill them both. Or the connector in the round wire near the firewall fell apart.

Dan
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It is a taxi light / landing light side by side on the left wing. I just had an annual done last month I would think they checked connections/grounding issues I only ask on here because I wanted to fly july 4th how would I know if it was just the bulbs that are bad? Seeing as the fuse is still good I cant imagine it being a ground issue
 
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Christopher said:
It is a taxi light / landing light side by side on the left wing. I just had an annual done last month I would think they checked connections/grounding issues I only ask on here because I wanted to fly july 4th how would I know if it was just the bulbs that are bad? Seeing as the fuse is still good I cant imagine it being a ground issue
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multi meter ?
 
Christopher said:
It is a taxi light / landing light side by side on the left wing. I just had an annual done last month I would think they checked connections/grounding issues I only ask on here because I wanted to fly july 4th how would I know if it was just the bulbs that are bad? Seeing as the fuse is still good I cant imagine it being a ground issue
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So you want to fly it on July 4th. What is to prevent you from flying it with the landing light inop?

Jim
 
weirdjim said:
So you want to fly it on July 4th. What is to prevent you from flying it with the landing light inop?

Jim
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Nothing at all it would just be nice :p I am just trying to see if it is a grounding issue or just bad bulbs ( how to tell )
 
Christopher said:
Nothing at all it would just be nice :p I am just trying to see if it is a grounding issue or just bad bulbs ( how to tell )
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Easy. Got an ohm meter (multimeter)? If not, got $5 and a Harbor Freight within striking distance? The test for filament continuity ain't rocket science.

Or, the voltmeter on that multimeter will serve the same purpose.

I sense a "Troubleshooting 101" column in Kitplanes coming out of this discussion.

Jim
 
If the fuse is good, it has to be either a ground fault or a bad hot wire. This isn't an uncommon issue in may light aircraft. Vibration and any degree of "looseness" in a wire connection and it's bound to happen.
 
May I also add after taking it up again my right fuel tank is now showing beyond full =\ lol cessnas are so silly.. Can this be a contributing factor/connected in some way?
 
Christopher said:
It is a taxi light / landing light side by side on the left wing. I just had an annual done last month I would think they checked connections/grounding issues I only ask on here because I wanted to fly july 4th how would I know if it was just the bulbs that are bad? Seeing as the fuse is still good I cant imagine it being a ground issue
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If you want to limit what you imagine it can be, you might as well just take it to an A&P. **** comes loose / blows out / breaks whenever. It's an electrical circuit, trace it, there is no part of it to exclude because you "can't imagine".
 
Christopher said:
May I also add after taking it up again my right fuel tank is now showing beyond full =\ lol cessnas are so silly.. Can this be a contributing factor/connected in some way?
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Sure sign of a bad ground....:yes::yes:
 
N801BH said:
Sure sign of a bad ground....:yes::yes:
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How? The tank ground is in the root of the wing and the landing light ground is about 2 meters further out to the forward spar? Not unless the whole wing has come loose, and then you've got more to worry about than fuel gauges and landing lights.

Jim
 
weirdjim said:
How? The tank ground is in the root of the wing and the landing light ground is about 2 meters further out to the forward spar? Not unless the whole wing has come loose, and then you've got more to worry about than fuel gauges and landing lights.

Jim
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How would corrosion at the wing bolts affect it? Granted given 3 attach points not very likely, or how about corrosion at the battery ground lug? Though that would affect radios as well.
 
Henning said:
How would corrosion at the wing bolts affect it? Granted given 3 attach points not very likely, or how about corrosion at the battery ground lug? Though that would affect radios as well.
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Because that would be the ground THROUGH the wing root rib, THROUGH the forward pseudospar, and then THROUGH the remaining floobydust connections back to the airframe and thence the rest of the electrical system.

The odds of this are roughly the same as winning a fight with an umpire or your significant other.

Jesus Murphy, people, five minutes with a Harbor Freight multimeter and you've got your answer. Why all this caterwauling about hyperremote possibilities that will only happen when Jupiter aligns with Mars and trines the Great Square of Pegasus?

You don't ... gasp ... suppose it could be a ... gasp ... burned out light bulb, do you?

Jim
 
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Run a #10 wire from the battery + post to the back of light bulb. then fix what smokes.
 
Tom-D said:
Run a #10 wire from the battery + post to the back of light bulb. then fix what smokes.
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Sigh..interesting you would write such a terrible idea after you light Henning up for a harmless tape measure measurement..
 
weirdjim said:
Because that would be the ground THROUGH the wing root rib, THROUGH the forward pseudospar, and then THROUGH the remaining floobydust connections back to the airframe and thence the rest of the electrical system.

The odds of this are roughly the same as winning a fight with an umpire or your significant other.

Jesus Murphy, people, five minutes with a Harbor Freight multimeter and you've got your answer. Why all this caterwauling about hyperremote possibilities that will only happen when Jupiter aligns with Mars and trines the Great Square of Pegasus?

You don't ... gasp ... suppose it could be a ... gasp ... burned out light bulb, do you?

Jim
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Yeah, that was what I suggested, I was pointing out the unlikeliness of it being common ground, sorry that didn't come through.
 
The landing lights are in the left wing and are dead. The defective fuel gauge is for the RIGHT tank and is reading overfull. Not related isues. The tank sender wire is grounded somewhere along its length, which takes resistance to zero and pegs the gauge.

Still might be a bad ground at the landing light assembly. There was often one ground wire to one bulb and a jumper to the other bulb. A break in the first wire kills both bulbs. There's also a connector in the left wing root that might be apart.

Dan
 
SbestCFII said:
If the fuse is good, it has to be either a ground fault or a bad hot wire. This isn't an uncommon issue in may light aircraft. Vibration and any degree of "looseness" in a wire connection and it's bound to happen.
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A ground faulty is a short and will blow the fuse. That's what fuses or breakers are for. This isn't a ground fault.

Dan
 
weirdjim said:
...that will only happen when Jupiter aligns with Mars...
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Interesting you should mention that because Jupiter is currently in conjunction with Venus.

As for the lights, well the number one cause of this phenomenon by a wide margin is a burned out bulb which normally occurs when you turn it on for the last time. If you look at it closely you can usually see if the filament is broken. So why would they both go out at exactly the same time? They probably didn't but close enough that you may not have noticed until they were both out.

Unlike the cowl mounted lights, which share a common ground through the disconnect, the wing mounted lights have separate grounds so are two completely individual circuits after the switch. They do however share a common source from the fuse to the switch.

So, as Jim pointed out, with a five dollar meter or even a test light, you could determine within minutes if you are getting 12 volts to the bulbs. It's been days already here on the internet and you've gotten nowhere. Step away from the keyboard and back into the real world.
 
Henning said:
If you lose the ground, what completes the circuit then?:dunno:
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Again, you are using wrong terminology. You keep calling it a ground fault, and it's already been explained to you what a ground fault is.

Henning said:
:confused: A ground fault is an open, not a short.
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A ground fault occurs when electricity travels outside an intended path and tries to get to the ground by the shortest route.
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Christopher said:
It is a taxi light / landing light side by side on the left wing. I just had an annual done last month I would think they checked connections/grounding issues
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You are kidding, right?

I only ask on here because I wanted to fly july 4th how would I know if it was just the bulbs that are bad? Seeing as the fuse is still good I cant imagine it being a ground issue
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Why would an open ground cause a fuse to blow?

Start at one end of the circuit with your voltmeter - Voltage into the fuse, voltage out. Voltage into the switch, voltage out. Voltage in the light connector. Continuity on the ground. Shouldn't take long. Don't forget to check the bulb.
 
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Henning said:
:confused: A ground fault is an open, not a short.
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Henning, that is incorrect.

RotorAndWing said:
Again, you are using wrong terminology. You keep calling it a ground fault, and it's already been explained to you what a ground fault is.
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R&W has it right.

A ground fault is an inadvertent contact between an energized conductor and ground or equipment frame. The return path of the fault current is through the grounding system and any personnel or equipment that becomes part of that system. Ground faults are frequently the result of insulation breakdown. It’s important to note that damp, wet, and dusty environments require extra diligence in design and maintenance. Since water is conductive it exposes degradation of insulation and increases the potential for hazards to develop.
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Ref: http://www.littelfuse.com/products/...tion-relay-pages/ground-fault-protection.aspx
 
Hey, folks, rather than debate how many ground loops can dance on the head of a pin, let's just let the fellow do some troubleshooting with the tips we've given him and let it go at that.

Lord knows there are enough pinheads in this group already. :goofy:


Jim
 
weirdjim said:
Hey, folks, rather than debate how many ground loops can dance on the head of a pin, let's just let the fellow do some troubleshooting with the tips we've given him and let it go at that.

Lord knows there are enough pinheads in this group already. :goofy:


Jim
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Agree, but it helps if he is getting good information.

I tend to start at one end...with the simple stuff...is there voltage going to the bulb? Check the socket for voltage, make sure those contacts are clean. Put an Ohm meter on the bulb- if there is infinite resistance on a filament bulb, the bulb is bad. If an LED bulb, I don't know enough- I think there are circuits that drive the LEDs?

If the bulb is good, and I'm not getting voltage, check the fuse/breaker and if those are good, find out where the electrons are going.
 
jesse said:
Sigh..interesting you would write such a terrible idea after you light Henning up for a harmless tape measure measurement..
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I understand you fail to see the sarcasm of trouble shooting on line.

And OBTW you'd be surprised at how effective this to find a weak ground.
 
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Cap'n Jack said:
Agree, but it helps if he is getting good information.

I tend to start at one end...with the simple stuff...is there voltage going to the bulb? Check the socket for voltage, make sure those contacts are clean. Put an Ohm meter on the bulb- if there is infinite resistance on a filament bulb, the bulb is bad. If an LED bulb, I don't know enough- I think there are circuits that drive the LEDs?

If the bulb is good, and I'm not getting voltage, check the fuse/breaker and if those are good, find out where the electrons are going.
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There is a standard method of troubleshooting called "binary troubleshooting". It goes like this...is there voltage at the very start of the circuit (the fuse). Is there voltage at the bulb terminal itself. (Landing lights don't have sockets; the bulbs have brass tabs with screw holes.) Is there zero voltage at the ground terminal of the bulb.

If so, troubleshooting over. Burned out bulb.

If no voltage at the fuse, find out why. If more than zero voltage at the ground terminal of the bulb there is an open ground.

Now split the circuit in the middle. What is left? Switch and any intermediate connectors. Voltage at the switch? Go to the connectors. Voltage at the connector(s)? Busted wire between connector and light terminal.

Troubleshooting over.

Jim
 
Tom-D said:
I understand you fail to see the sarcasm of trouble shooting on line.

And OBTW you'd be surprised at how effective this to find a weak ground.
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Plus this will eliminate the power supply side of the circuit, by either lighting the bulb, or not. it will also show a blown bulb.
When you touch the wire to the hot side of the bulb and it lights the bulb you have a power problem. if it doesn't light the bulb you either have a bad bulb, or a bad ground.

So now tell me again how bad that suggestion was.
 
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