tail position light wiring

[jon s. blocker]

Does anyone have a picture of how the tail position light wiring is run in an 18 rudder, and where it exits the fuselage? I am covering the tail feathers for a friend, and the wiring was already removed before I got them. It has a post light, and a rear position light. Don't know which, or both, he will use, I'll just wire for both. Thanks for any help. Jon

 

[mike mcs repair]

depends on type of lights and wire size.... and where terminated on fuselage

 

[Steve Pierce]

Usually a hole in the rib for a grommet and the wire to run through. I will see if I have a picture.

 

[wireweinie]

Just info: Use shielded wire for the nav or strobe lights inside the rudder. Connect the light unit's ground wire to one end of the shield and connect the other end to airframe ground. This ground circuit eliminates the flickering lights that happen as the rudder is moved. Also, a shielded wire allows you to route a 'single wire' that has two (or more, as needed) conductors. I.e. using a single conductor, shielded wire for a beacon or simple tail nav, allows you to connect power through the center conductor and ground through the shield. If you install an LED nav/strobe combo unit, use three conductor, shielded wire. 1) power for strobe 2) power for nav 3) synch wire 4) shield connected for ground path.

Most Cubs have the wires exit the rudder at the lower left side just below the steering arm. It's a good idea to install a connector of some sort here, in case you need to remove the rudder. Try to adjust the length of wire, to that connector, so that it is stowed inside the fuselage, not outside. Protects it from the elements and corrosion.

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[mike mcs repair]

If you ground both ends of shield you negate the shields effectiveness as then it may be a conductor and have flow

 

[wireweinie]

If you ground both ends of shield you negate the shields effectiveness as then it may be a conductor and have flow

That is correct. However connected, as I described, only one end of the shield is connected to ground. The other end is connected to the 'ground' lead (-) coming off the light assembly.

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[jon s. blocker]

Thank you for all your help. I got with the guy I'm doing this for and he gave me all of the wiring and all of the lighting equipment. He had everything I need to complete the cover, and showed me where he wanted the wire to exit the rudder. Again, thank you all for your quick responses. Now if I can just get my other buddies brakes on his Zenair floats to work, I can eventually get back to working on my wings! Cub Crafters master cylinders and Grove calipers won't hold on run-up with a Cont-0-200. Won't even steer on taxi. Jon

 

[bob turner]

My Grove calipers are identical to the calipers on my 180 hp Decathlon, and both hold the same. Sure you have the pads conditioned properly? We can lock wheels with Grove calipers.

 

[Aerodon]

I have a 1993 cub, and can take pictures of the strobe wiring exit locations. They did the proper thing, used a 4 pin molex connector to join the rudder to the fuselage - 4th pin to run the shield through, which ends at the 3 pin molex at the strobe. Agree, don't ground the shield at the end.

Aerodon

 

[wireweinie]

To be clear about the use of the braided shield on a wire: there are two different ways of using this. As a shield and as a conductor.

To use the braid as a shield to prevent electrical noise, separate sections may be connected in series, but only one end of the run is connected to airframe ground. No other connections are made to ANY other points. This insures that strong magnetic signals generated by any conductors close by, will be picked off by the shield and conducted directly to ground. If you connect both ends of the braid to ground, you have an alternate ground path for any signal (airframe OR the braid) from any other circuit in that airframe area. This can lead to excessive noise. If that alternate ground gets used by an audio circuit nearby (isolation washers on the jacks prevent this, by the way) you'll get a 'squeal' in you headset.

To use the braid as a conductor, as I described in post #4, you connect one end of the shield to the ground lead of a component, in this case an LED light assembly. Multiple sections can be connected in series, but the opposite end of the run is then connected to airframe ground. This use is not a true 'shield' as the ground circuit of the component is using it as a conductor to ground. A couple advantages are size and secure grounding. Size because you are using, in the case of the LED lights, three conductors inside of a braid. Very compact, easy to route, and has the effect of installing one wire instead of four separate wires. Secure grounding because you have the option of connecting the braid to ground at a location free from paint, powdercoat, and seams in the frame. It bypasses poor grounding from wings and rudders due to hinge and spar connections. I usually route the shield to ground forward of the instrument panel, as the conductors are routed to that area for connection to the switches.

Clear as mud?

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