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Problem with Nav and Taxi lights

RedRaider94

Active Member
I have been doing some work on the EFIS systems and created a new problem that I am struggling to diagnose. When I turn on the Nav lights, both light up well on the wings. When I then turn on the landing lights, they come on as normal on the left wing along with the red light staying bright, but on the right wing, the green light dims to almost not noticeable and the landing light is on but not as bright as normal.

If I turn any of the lights on in isolation but when I turn on the nav lights in addition, the left wing is fine but the right wing has dimmer lights.

I also notice on the g meter that is backlit, when I flip the mag light, the backlight dims like it is no getting as much power. It doesn?t dim when I turn on the landing or taxi lights.

This is all with just battery power.

Any thoughts on what I might have messed up or ideas on what could be happening so I can try to eliminate potential causes to figure out the actual issue?

Thanks!
 
Without knowing how you wired your plane, it would be tough to guess why the EFIS installation would cause it.

How did you ground the nav and ldg lights? Back to a common ground or a frame ground? Do you have a connector at the wing/fuse intersection? I would start with these two areas. The problem has to be after the wiring splits for the two different wing runs, as the problem only appears on one branch of a shared circuit.

Larry
 
I didn?t build it so I am trying to trace back how it is wired. I did take the light brackets out to get a look inside the wing. I could see a 4 prong connector that is riveted to one of the wing sections with 4 black wires coming off and leading to each of the 4 lights (landing, taxi, nav, and strobe). Maybe this problem has been going on for a while and I just didn?t know it.

I did replace both strobes last week but that is just a 3 plug molecules connection.

As I think through it, that has to be the only place (common ground) that the lights have in common but it is just a ground. Anything specific I should be looking for or testing?
 
I'm not qualified to address anything aviation, but in automotive situation a light that dims when an additional load is introduced to the circuit is most often an indicator of a poor ground on the circuit or at a load on the circuit.
 
I'm not qualified to address anything aviation, but in automotive situation a light that dims when an additional load is introduced to the circuit is most often an indicator of a poor ground on the circuit or at a load on the circuit.

Exactly.

My guess is you are using the airframe as the ground path. Works most of the time but also can be problematic. I always provide a wired ground path back to the firewall ground block for everything.

Carl
 
You all nailed it. The ground in the wing was the problem. All better now and appreciate the guidance on where to look!
 
But, but....

I am SO glad that I ran wires for discreet grounds. As previously stated, airframe grounds work fine...until they don't...
 
I am SO glad that I ran wires for discreet grounds. As previously stated, airframe grounds work fine...until they don't...

What to you think about the situation, (I am thinking of Aeroled VX Sun and Pulsar lights), where the manufacturer specifically requests that the grounds be done locally at the airframe?
 
What to you think about the situation, (I am thinking of Aeroled VX Sun and Pulsar lights), where the manufacturer specifically requests that the grounds be done locally at the airframe?

Local shield grounds for RF noise are a consideration. DC ground at the firewall for power is another. No reason not to do both. That is what I do with my AeroLED install and enjoy no RFI.

Carl
 
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