Mag switch

[kevinbrooker]

I've traced some ignition hassles to the mag switch. Anyone have one to sell or know where I can get one without a start position. I just ant an OFF, L,R, Both. Thanks, Kevin

[Hank Jarrett]

Which kind of mag switch? I have been modifying the old A-7 and A-9 switches when they fail by using the lever and face plate and mounting a key in the lever and putting a Grimes or other more modern switch behind it in the panel. Looks original but more reliable. DO NOT TRASH broken or worn out A-7 or A-9 switches!!!

[kevinbrooker]

I have the switch (no idea of the part number) which looks like what is on the light blue stripe. I'd like to keep the original look. What Grimes switch do you recommend and do you have drawings for the mod you suggest?

[Robert Lees]

I have overhauled several A7 mag switches with varying degrees of success. A common failure is wearing on the internal brass/copper contacts, which causes tiny particles of metal to start causing short-circuits. A good clean and then reassembly with dielectric grease (like Dow Corning 4) commonly resolves the problem.

The issues are generally two-fold:
1. You have to bend three of the four "grips" that hold the case to the fibre backplate...if these break, you're stuffed.
2. The internals may be so worn away that overhaul is just not possible

Hank is right though; never throw anything away!
But mag switches are a safety-critical item, so please do what you have to do, in order to prevent a live mag!

One of my Taylorcraft is operated by several pilots, and I have installed a standard Bendix keyswitch for the duration. If & when I ever sell it (or more to the point: my Executors sell it), the old (but serviceable) A7 will go back in for authenticity.

Rob

[3Dreaming]

The article on the modification was first printed in Vintage Airplane magazine sometime after October 1994. It was based on the switch I modified for my grand champion BL-65 Taylorcraft. It was also reprinted in the Taylorcraft news letter, and the Cub and Luscombe news letters.

[Hank Jarrett]

The beauty of what I did is only the cosmetic parts of the original mag switch were re-used. The more modern switch is simply mounted to a plate behind the hole with spacers. Hard part was getting the key centered in the lever and both centered so they were in the right location and depth when the key was put in. It actually works great just putting the key in the slot without the lever. If I want the mags "locked" I just put the 45 lever in the 41 and 41 lever in the 45. They won't turn. Wrong key. It is nice to be able to walk away from the plane and it can't be started (unless of course someone simply cuts the P lead) by pulling the lever and key out.