• The Biplane Forum is a large global active community of biplane builders, owners and pilots. From Pitts to Skybolts, to older barnstormers, all types are welcome. In addition to our active community, our content boasts exhaustive technical information which is often sought after for projects and maintenance. This information has accumulated over the 12+ years the forum has been in existence.

    The Biplane Forum is a private community. Subscriptions are only $29.95/year to gain access to this great community and unmatched source of information not found anywhere else on the web. We are also a great resource for non biplane users, since many GA aircraft are built the same way (fabric and tube construction).

Honeywell Microswitches: Master and L/R mags (or for other things :) )


Well-Known Member
Lifetime Supporter
May 3, 2013
Reaction score
Central Texas

Have three new Honeywell microswitches that I ended up not using in my electrical rebuild...

There's nothing wrong with them; but I ended up not liking how locking was set up on them (for example, I wanted Master to be locked in the ON as well as OFF position, but with the one I had I could only lock it in the OFF position).

Here are the switches:

2TL1-10F - progressive, locked out in "OFF" position, ideal for a "master" switch (center position turns on your battery, full "up" turns on your alternator). New price ~$65


2TL1-5F - DPDT with springloaded "top" position, locked out in the full off position. New price ~$35

2TL1-1L - DPDT, locked out of the top position ~$55

Now, the last two were destined to be 2 switches controlling both mags and start. Here's the diagram:


Switch down: mag is off
Switch in the middle position: mag is on (ungrounded)

Right mag switch goes up: right mag turns off, 1/2 of the starter circuit complete
Left mag switch goes up: left mag stays on, starter circuit complete 100%

(remember, starting setup is "left mag on only, starter contactor powered")

These switches are premium milspec switches and are much less crunchy than typical "commercial" switches. Back sides are #6 ring terminals.
Honeywell microswitch specs (including full diagrams and part ## decoder): https://sensing.honeywell.com/honeywell-sensing-micro-switch-tl-toggle-product-sheet-005430.pdf

Now, to the price :) $75 for all three + shipping (Priority Mail - small box - whatever the going rate is today?)


Latest posts