Cleaning Ignition Harness contacts ?

[Indiana_Pilot]

I have searched through the manual and I cannot find anything that states how to clean these. I just changed my plugs in my Cherokee 180 over to Fine Wires and I noticed some of the contacts under the spring on the ignition leads could use some cleaning too.. It doesn't look like they have been arcing but some look a little Dirty?

What is the safest way to clean them? I am thinking maybe a pencil eraser or can I be more aggressive?

Also, since I am allowed to change my plugs, am I allowed as an owner to change the ignition leads if I wanted to?

 

[Tom-D]

I have searched through the manual and I cannot find anything that states how to clean these. I just changed my plugs in my Cherokee 180 over to Fine Wires and I noticed some of the contacts under the spring on the ignition leads could use some cleaning too.. It doesn't look like they have been arcing but some look a little Dirty?

What is the safest way to clean them? I am thinking maybe a pencil eraser or can I be more aggressive?

Also, since I am allowed to change my plugs, am I allowed as an owner to change the ignition leads if I wanted to?

NO...

 

[Capt. Geoffrey Thorpe]

You can change anything you want. You just can't sign the log entry.

 

[flyingron]

You can change anything you want. You just can't sign the log entry.

Anybody can make a plane UNAIRWORTHY

 

[Anticept]

Are you talking about where the spring attaches to the screw, which goes into the harness? If so, NO. Don't clean it. Due to the high voltage that is carried, if you damage it or use the wrong cleaners, you will greatly accelerate wear. The leads will tolerate carbon, what they won't tolerate is corrosion or your greasy fingers on them

Your maintenance manual for your airplane should have an ignition harness section in it which will show you how these are assembled (for your knowledge). But basically, the spring has a tightly coiled end, which is threaded onto a pin, which is inserted into the end of the lead. It has many, many points of contact.

You can also get a copy of the manuals for harnesses from bendix or slick, depending on what you have.

 

[Tom-D]

But basically, the spring has a tightly coiled end, which is threaded onto a pin, which is inserted into the end of the lead. It has many, many points of contact.

You can also get a copy of the manuals for harnesses from bendix or slick, depending on what you have.

The TCM harness have had swaged ends for years.
They require a special tool to swage the end on when you set the ends back to fresh material.

 

[Anticept]

The TCM harness have had swaged ends for years.
They require a special tool to swage the end on when you set the ends back to fresh material.

I don't have bendix or TCM harness manuals to see what you are talking about.

On lycomings with slick magnetos (the models I worked on, anyways), it has a drive ferrule (let's call it an "inner" sleeve") that the nut ferrule ("outer" sleeve) binds to, with the ground shielding wedged between. The ferrule nut clamps down on the shielding wedged in between and keeps strain off of the core and the spring. They too need a special tool. This does not have anything to do with how the spring is connected to the high voltage core of the lead, however, or the ignition system wouldn't work because it would ground it out . Cherokee 180's use lycomings from the factory.

I'll see if I can find something on the TCM/bendix harness, but I don't work on continentals/bendix systems right now, so I'm not going to buy them.

EDIT: as said in the other topic, didn't realize you are a mechanic. So nevermind the "lesson"

 

[Tom-D]

On lycomings with slick magnetos, it has a drive ferrule (let's call it an "inner" sleeve") that the nut ferrule ("outer" sleeve) binds to, with the ground shielding wedged between. The ferrule nut clamps down on the shielding wedged in between and keeps strain off of the core and the spring. They too need a special tool. This does not have anything to do with how the spring is connected to the high voltage core of the lead, however, or the ignition system wouldn't work because it would ground it out . Cherokee 180's use lycomings from the factory.

Unless you have the tools and training I'd suggest you not try to repair any of the TCM or Slick harness. many are resisted leads and can't be successfully repaired. Many of the after market leads are that way too.

 

[Anticept]

Unless you have the tools and training I'd suggest you not try to repair any of the TCM or Slick harness. many are resisted leads and can't be successfully repaired. Many of the after market leads are that way too.

This one can, and I have the training, manuals, and tools for it.

Are you referring to the harnesses that use resistors in the leads instead of in the plugs?

 

[Tom-D]

This one can, and I have the training, manuals, and tools for it.

Are you referring to the harnesses that use resistors in the leads instead of in the plugs?

Are you an A&P?

 

[Anticept]

Yes. Admittedly, a little young with it still, but I'm always studying. Another year and a half and I'll go for my IA test.

I learned how to work with harnesses from school.

My circumstances are a little different from most mechanics. Since I run a flight training organization, I am able to afford devoting time to studying the mx manuals while instructors are teaching students. I also recognize that I am still inexperienced, so I send our aircraft out for the annuals to another shop, including the light sports, even though I can do the annual condition inspections on those. I like lots of eyes. When I deal with an aircraft that I haven't worked with before, I take it to another shop that I work with to get some training on it. If there's major repairs, I send that out too, I'm not quite confident enough to put my neck out that far, or bet anyone's life on it. Some day I will, and the work I do will be fantastic. But not there yet!

 

[Silvaire]

In general you don't have to clean these contacts unless you see some serious corrosion buildup. The magneto produces a potential of several thousand volts, enough to jump the air gaps between the rotor wiper and terminal as well as the plug electrodes. If a lead contact, or anything in the circuit were to pose a serious impedance or resistance to that potential you are going to see evidence of a tremendous amount of heat which would discolor or even melt the lead end insulation or other surrounding components.

 

[yetti]

rubbing a1coho1 to c1ean is what I was taught

 

[Geico266]

How can cleaning something be illegal? Wiping out the contacts with a Q-tip and alcohol will make the plane un-airworthy? I'm calling BS.

 

[Anticept]

I don't think anyone said that specifically would make something unairworthy.

 

[Silvaire]

How can cleaning something be illegal? Wiping out the contacts with a Q-tip and alcohol will make the plane un-airworthy? I'm calling BS.

Calm down, he asked about replacing them, not cleaning them.

Also, since I am allowed to change my plugs, am I allowed as an owner to change the ignition leads if I wanted to?