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Paul Johnson

Member
I'm trying to figure out how to wire my ignition switch. I have an Aerosport O-360-A1A with a mag on the left and LS Plasma II+ on the right side. The mag needs its P-lead grounded to be OFF and the LS needs 12v power to be ON. I'm also trying to use a conventional OFF-R-L-BOTH-START keyswitch. I thought about using a relay to invert the logic (NC contacts would provide power to the LS system when the relay is not energized), but that would leave the LS system "hot" when the keyswitch is OFF and master power is ON. Am I overlooking a simple solution, or do I need to abandon the keyswitch idea and go to a couple of toggle switches and a pushbutton starter control? My only opposition to this is the big hole it would leave in my panel.

Other must have faced this issue before, but a search did not turn anything up.
 
NOOOOO. No relays!
Wire the box to the 12v source as indicated in the input connector diagram Pin 8. You can do this any which way. If Pin 8 has +12 your good.

Wire the output connector to your key switch as indicated in the installation procedures.
Use the key switch to switch ground.
Following the diagrams here .

If pins 1&9 of the output connector are closed (ie via the key switch), the ignition is disabled just like your p-lead mag. If they are open, your ignition is hot.

come back here if you have any questions. Installation manual is pretty detailed in this regard.

Also use an ohm meter to make darn sure you know which pins on the key switch are switching when. You can decide for yourself whether or not you want the LSE off during start or not. That debate goes on in other threads.
 
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However mine is wired I get no RPM when I switch to the LSE unit. No problem since I can tell by sound that it is essentially the same RPM as with both mag and LSE running.
 
Use seperate switches

There is lots written on this, but probably hard to search for. Kahuna is right, the LS has the MAG switch option standard now I recall. Older units don't and you can't use a key mag switch.

They are TWO different systems, keep them that way.

Key switches kind of suck. They are cool on a Cessna but I would suggest two separate switches and a push to start button.

Even top O line fancy cars have push start.

Yes there is something CAR LIKE and convenient with a KEY switch that runs two ignitions and the starter. However it is VERY airplane like to have seperate mag switches and starter switches and master switches in airplanes.

Most larger planes and twins have separate switches.

Only the "traditional airplane" since the 60's have really used key switches.

Don't tie you whole life to one switch.
 
You need keys

You should note that there is now an FAA/TSA requirement for airplanes to have two forms of locks to stop someone from taking your airplane. Typically, the door or canopy lock, and the ignition key lock satisfy this requirement. If you use switches and push button start, you are missing one of your keys. Then you need a throttle lock, or something like that.

Enforcement of this probably highly variable depending on DAR's, etc. but it is a real requirement. Sorry I can't find the citation right now, but someone can.
 
Locks & key switches

This TSA aircraft locking business was discussed in the forum about 6-8 mo ago as I recall. The conclusion was it has narrow application and does NOT apply to EAB aircraft.

I had a mag switch fail on me once... failed to ground the mag.... so I don't trust the thing. I'm planning to use an ON-OFF key switch... but only to keep the honest people honest.... it will only interrupt the start PB circuit to the starter solenoid. A thief would have to hand prop the plane, and with any luck will hack off his arms in the process!!

My Mag & LSE ign will have separate toggle type switches.
 
I also have a mag and LSE setup and didn't want to have a normal mag/start switch. The problem was finding a simple momentary keyswitch.
Most were either huge industrial machine affairs or total junk.

I found this switch at Digi-key and it works great. (Lousy photo-sorry)

startswitchhf6.jpg


If anybody's interested I can dig out stock # for the switch

Paul Danclovic
Albuquerque NM / Carver MN
RV-8A N181SB
 
correction - two locks voluntary except NJ, PA

Hi,
I did a bit more research - apparently the requirement for two locks that was drafted by the TSA is VOLUNTARY. However, New Jersey seems to have made it a requirement, and Pennsylvania is trying to it too, although AOPA is fighting it.
 
States can stick it....

Just as States can't regulate use of nuclear energy over the NRC, IMHO States have no authority to usurp FAA regulatory authority over the use/operation of aircraft. The reasons are self evident!! But... that sure doesn't stop state and local bureaucrats from trying to muscle in! Urrggggg.... I hate bureaucrats!!:mad:
 
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