Mag switch O/H, repair???

After 6 years of Mooney ownership my squawk list is getting pretty
small. One thing that really bothers me is a new mag switch that was
installed 4 years ago (the key switch). Sometimes I can easily start
the plane, sometimes it seems like I have to hunt for the magic key
position that will engage the starter. I find myself moving the key
back and forth trying to engage it. When I hit it, the prop turns
right away.
Short of replacing the switch again, is there a place I can send my
existing switch during annual to have it worked on?

-Robert

If it is like the Mag switch on a PA28-180, it is a simple beast and perhaps
your local shop could overhaul it. Mine would hang up in the off position
and require repeated jiggling to get it unlocked (from your description I'm
assuming this isn't the same symptom.) The hardest part was getting the
half dozen or so wires labeled and unscrewed from the back terminals before
removing it from the panel. When it was disassembled on the bench, fine
metal particles fell out that were intermittently hanging up the lock
fingers. The particles were associated with the lock and had nothing to do
with the contactor section of the switch. After cleaning it up and
resolving to never try to turn the switch when the key was not completely
forward, the problem was resolved.

Have you isolated the problem to the switch? Sounds like it could also be a
starter or some other downstream problem.

--
Best Regards,
Mike

http://photoshow.comcast.net/mikenoel

Time flies like an arrow, fruit flies like a banana.

"Robert M. Gary" wrote in message
oups.com...
After 6 years of Mooney ownership my squawk list is getting pretty
small. One thing that really bothers me is a new mag switch that was
installed 4 years ago (the key switch). Sometimes I can easily start
the plane, sometimes it seems like I have to hunt for the magic key
position that will engage the starter. I find myself moving the key
back and forth trying to engage it. When I hit it, the prop turns
right away.
Short of replacing the switch again, is there a place I can send my
existing switch during annual to have it worked on?

-Robert

On Mar 19, 11:24 am, "Mike Noel" wrote:
If it is like the Mag switch on a PA28-180, it is a simple beast and perhaps
your local shop could overhaul it. Mine would hang up in the off position
and require repeated jiggling to get it unlocked (from your description I'm
assuming this isn't the same symptom.) The hardest part was getting the
half dozen or so wires labeled and unscrewed from the back terminals before
removing it from the panel. When it was disassembled on the bench, fine
metal particles fell out that were intermittently hanging up the lock
fingers. The particles were associated with the lock and had nothing to do
with the contactor section of the switch. After cleaning it up and
resolving to never try to turn the switch when the key was not completely
forward, the problem was resolved.

Have you isolated the problem to the switch? Sounds like it could also be a
starter or some other downstream problem.

--
Best Regards,
Mike

http://photoshow.comcast.net/mikenoel

Time flies like an arrow, fruit flies like a banana.

"Robert M. Gary" wrote in ooglegroups.com...



After 6 years of Mooney ownership my squawk list is getting pretty
small. One thing that really bothers me is a new mag switch that was
installed 4 years ago (the key switch). Sometimes I can easily start
the plane, sometimes it seems like I have to hunt for the magic key
position that will engage the starter. I find myself moving the key
back and forth trying to engage it. When I hit it, the prop turns
right away.
Short of replacing the switch again, is there a place I can send my
existing switch during annual to have it worked on?

-Robert- Hide quoted text -

- Show quoted text -

The A&P I usually work with says "Wow, those things are complicated
inside" so I don't think he would want to disassemble one. However, if
you think its the way to go, I could just walk it into a local FBO
shop and ask them to look at it. I really think its the key because it
seems like sometimes I'm turning the key beyond the start position and
moving it back engages the starter. It also seems to happen more on
hot days (when we're all sweaty in the plane).

-Robert

On Mar 19, 1:50 pm, "Robert M. Gary" wrote:
On Mar 19, 11:24 am, "Mike Noel" wrote:





If it is like the Mag switch on a PA28-180, it is a simple beast and perhaps
your local shop could overhaul it. Mine would hang up in the off position
and require repeated jiggling to get it unlocked (from your description I'm
assuming this isn't the same symptom.) The hardest part was getting the
half dozen or so wires labeled and unscrewed from the back terminals before
removing it from the panel. When it was disassembled on the bench, fine
metal particles fell out that were intermittently hanging up the lock
fingers. The particles were associated with the lock and had nothing to do
with the contactor section of the switch. After cleaning it up and
resolving to never try to turn the switch when the key was not completely
forward, the problem was resolved.

Have you isolated the problem to the switch? Sounds like it could also be a
starter or some other downstream problem.

--
Best Regards,
Mike

http://photoshow.comcast.net/mikenoel

Time flies like an arrow, fruit flies like a banana.

"Robert M. Gary" wrote in ooglegroups.com...

After 6 years of Mooney ownership my squawk list is getting pretty
small. One thing that really bothers me is a new mag switch that was
installed 4 years ago (the key switch). Sometimes I can easily start
the plane, sometimes it seems like I have to hunt for the magic key
position that will engage the starter. I find myself moving the key
back and forth trying to engage it. When I hit it, the prop turns
right away.
Short of replacing the switch again, is there a place I can send my
existing switch during annual to have it worked on?

-Robert- Hide quoted text -

- Show quoted text -

The A&P I usually work with says "Wow, those things are complicated
inside" so I don't think he would want to disassemble one. However, if
you think its the way to go, I could just walk it into a local FBO
shop and ask them to look at it. I really think its the key because it
seems like sometimes I'm turning the key beyond the start position and
moving it back engages the starter. It also seems to happen more on
hot days (when we're all sweaty in the plane).

-Robert- Hide quoted text -

- Show quoted text -

Those things aren't all that difficult. You don't even
have to take the wires off the back IF you can get at the switch
easily enough. We take the switch out of the panel, leave the wires
connected, remove the two screws from the back of it, and lift off the
back cover. There are usually three triangular contact plates in the
rotating plate that run across numerous different contact strips on
the back cover, with small springs behind the triangles to keep them
in contact with the strips. The light grease used to lubricate the
contacts gets old and stiff and prevents conduction, and sometimes the
starter switching contacts get burned a bit. The coil in the starter
solenoid does that by generating a voltage spike to cause some arcing
in the switch. See this:
http://www.airweb.faa.gov/Regulatory...F?OpenDocument

Dan

Dan