74 Archer ignition switch question

These switches are made by Bendix and usually cost around $275 and up.
When you say it "locks up", do you mean that you insert the key in the
slot and the switch will not turn from the "off" posisition? Can you
remove the key easily from the off position when it does this?

Here are a few things to try. First, remove the switch from the panel,
mark down the connections and remove the connections from the switch.
Next, take out the 3 screws holding the thing together. Inspect the
springs and contacts to see if any of them are broken, bent, deformed,
burned, etc. If so, try to clean and/or repair them (180 grit sandpaper
followed by a good cleaning with contact cleaner). Reassemble and see if
it still locks up. If not, the contracts were the problem. I believe
Wag-Aero has an "overhaul kit" that consists of new contacts and
springs. Wag also has new units (push to start and the other kind).

If it still locks up and the contacts/springs looked good and clean, it
is probably the lock itself. A locksmith should be able to disassemble
it and put in new pins or repair it for a lot less than a new complete
unit will cost. These are pretty simple locks. If you have 10,000 hours
on the beast you might consider replacement though.

Good Luck,
Mike




My ignition switch occasionally locks up (with the key inserted) in the off
position when I try to start the engine.
.stuff snipped
The parts manual indicates 10-357210-1 for my serial number PA-28-180, but
that part has a push function in the start position (for priming?) that my
aircraft doesn't have. The other choice in the manual is 10-357200-1 that,
from the description, sounds like my switch.

Has anyone similarly found that their PA-28-180 uses the non-push ignition
switch instead of the push type called out in the manual? I'm guessing the
'push to prime' feature is for IO engines instead of O type that is stock on
Archers.

This one has at the most 3400 hours of use if it is the original switch.
Chief sells the 'no push' version with a 'start' position for about $210. I
believe I'll take a stab at fixing it before buying a new one.
It is the lock that will not let go because it won't turn to the right at
all. The 'no push' version can be had with or without the 'start' position.
I hope that means the 'start' position is a spring loaded twist position
that engages the starter.

--
Best Regards,
Mike

http://photoshow.comcast.net/mikenoel

"Mike Spera" wrote in message
nk.net...
These switches are made by Bendix and usually cost around $275 and up.
When you say it "locks up", do you mean that you insert the key in the
slot and the switch will not turn from the "off" posisition? Can you
remove the key easily from the off position when it does this?

Here are a few things to try. First, remove the switch from the panel,
mark down the connections and remove the connections from the switch.
Next, take out the 3 screws holding the thing together. Inspect the
springs and contacts to see if any of them are broken, bent, deformed,
burned, etc. If so, try to clean and/or repair them (180 grit sandpaper
followed by a good cleaning with contact cleaner). Reassemble and see if
it still locks up. If not, the contracts were the problem. I believe
Wag-Aero has an "overhaul kit" that consists of new contacts and springs.
Wag also has new units (push to start and the other kind).

If it still locks up and the contacts/springs looked good and clean, it is
probably the lock itself. A locksmith should be able to disassemble it and
put in new pins or repair it for a lot less than a new complete unit will
cost. These are pretty simple locks. If you have 10,000 hours on the beast
you might consider replacement though.

Good Luck,
Mike




My ignition switch occasionally locks up (with the key inserted) in the
off position when I try to start the engine. .stuff snipped
The parts manual indicates 10-357210-1 for my serial number PA-28-180,
but that part has a push function in the start position (for priming?)
that my aircraft doesn't have. The other choice in the manual is
10-357200-1 that, from the description, sounds like my switch.

Has anyone similarly found that their PA-28-180 uses the non-push
ignition switch instead of the push type called out in the manual? I'm
guessing the 'push to prime' feature is for IO engines instead of O type
that is stock on Archers.

News flash...I removed and disassembled the switch as suggested. The only
difficult part of the operation was reconnecting the 5 screw-down connectors
during reassembly.

As I was taking it apart on a clean rag, I noticed small shiny metal
fragments laying on the rag. Looking inside the lock casing, I could see
the outer corner of the trough the lock tumblers locked into was eroded.

Evidently that edge has been eroding for a while to create that tiny pile of
fragments. Each time it took a little extra effort to turn the key from the
locked position, the tumblers were not completely retracted by the key a bit
of metal was chewed from the edge. This was probably initially caused by
aging lubricant in the 30 year old lock.

I think the most recent hard lockups were caused by the metal fragments
preventing the tumblers from retracting. Jiggling the key eventually
knocked loose the offending fragment and allowed to lock to work again for a
while.

I've got my fingers crossed that removing the metal fragments from inside
the lock has solved the problem. Probably some light lubricant in the slot
occasionally should keep the tumblers free and avoid the internal edge
chipping. Thankfully, the way the lock is constructed didn't allow the metal
fragments to reach the internal switch contacts.

--
Best Regards,
Mike

http://photoshow.comcast.net/mikenoel

"Mike Noel" wrote in message
. ..
This one has at the most 3400 hours of use if it is the original switch.
Chief sells the 'no push' version with a 'start' position for about $210.
I believe I'll take a stab at fixing it before buying a new one.
It is the lock that will not let go because it won't turn to the right at
all. The 'no push' version can be had with or without the 'start'
position. I hope that means the 'start' position is a spring loaded twist
position that engages the starter.

--
Best Regards,
Mike

http://photoshow.comcast.net/mikenoel

"Mike Spera" wrote in message
nk.net...
These switches are made by Bendix and usually cost around $275 and up.
When you say it "locks up", do you mean that you insert the key in the
slot and the switch will not turn from the "off" posisition? Can you
remove the key easily from the off position when it does this?

Here are a few things to try. First, remove the switch from the panel,
mark down the connections and remove the connections from the switch.
Next, take out the 3 screws holding the thing together. Inspect the
springs and contacts to see if any of them are broken, bent, deformed,
burned, etc. If so, try to clean and/or repair them (180 grit sandpaper
followed by a good cleaning with contact cleaner). Reassemble and see if
it still locks up. If not, the contracts were the problem. I believe
Wag-Aero has an "overhaul kit" that consists of new contacts and springs.
Wag also has new units (push to start and the other kind).

If it still locks up and the contacts/springs looked good and clean, it
is probably the lock itself. A locksmith should be able to disassemble it
and put in new pins or repair it for a lot less than a new complete unit
will cost. These are pretty simple locks. If you have 10,000 hours on the
beast you might consider replacement though.

Good Luck,
Mike




My ignition switch occasionally locks up (with the key inserted) in the
off position when I try to start the engine. .stuff snipped
The parts manual indicates 10-357210-1 for my serial number PA-28-180,
but that part has a push function in the start position (for priming?)
that my aircraft doesn't have. The other choice in the manual is
10-357200-1 that, from the description, sounds like my switch.

Has anyone similarly found that their PA-28-180 uses the non-push
ignition switch instead of the push type called out in the manual? I'm
guessing the 'push to prime' feature is for IO engines instead of O type
that is stock on Archers.