Alternator whine

"RST Engineering" wrote in message
...
A coup'la questions & comments:

1. Why would you disconnect the battery to replace the alternator?

I suspect it was in an attempt to reseat all connections that could
contribute to the problem. I had already done this as well as "moving" all
of the alternator mounting bolts. I didn't try any magic juice, however.


2. One presumes certain basic troubleshooting procedures prior to
throwing parts at the problem, like back all heavy nuts grounding the
alternator, squirt in a little magic juice, and retighten.

I'll emphasize that I did my own diagnosis and concluded that it was an open
diode. I took it to the shop not to have them diagnose but to swap the
alternator - which they did quite well and it (or the process of doing it)
solved the problem.

-------------------------------
Travis
Lake N3094P
PWK

"Travis Marlatte" writes:

1. Why would you disconnect the battery to replace the alternator?

I suspect it was in an attempt to reseat all connections that could
contribute to the problem. I had already done this as well as "moving" all
of the alternator mounting bolts. I didn't try any magic juice, however.

A wise move...

And I always pull the battery ground before I swap an alternator or
such. Then, when I drop the wrench or such; that precaution cuts
down on the "sparky-do's" as an old cow orker used to called it.

I've no doubt it's now a Terrorist Act to take an aircraft alternator
to an autoparts store for testing; but if it were from an airboat,
[YES, that's it, an IO-540 in an airboat....] then you might go that
route. The trouble is, will Al Autozone know how to hook up an
alternator sans regulator?

I wonder if aircraft will ever get internal regulators as cars have
had for 20+ years. It really cuts down on the number of wires to
come lose & cause weird grief...

--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

"David Lesher" wrote in message
...


And I always pull the battery ground before I swap an alternator or
such. Then, when I drop the wrench or such; that precaution cuts
down on the "sparky-do's" as an old cow orker used to called it.

'splain, Lucy, how you get sparky-do's with the master off and tagged?
Especially if you are working by yourself.



I've no doubt it's now a Terrorist Act to take an aircraft alternator
to an autoparts store for testing

I did NOT say take it to an autoparts store; please don't put words in my
mouth. I said take it to a shop that specializes in automobile battery
electrical systems. They are as far removed from an Autozone hamhand as a
filet mignon is from a mcburger.



; but if it were from an airboat,
[YES, that's it, an IO-540 in an airboat....] then you might go that
route. The trouble is, will Al Autozone know how to hook up an
alternator sans regulator?

Probably not, but an automotive electric system specialist will...(s)he had
to work on them 30 years ago and the test jig is still on the back shelf for
Old Man Waverley's Studebaker that he brings in every 10 years or so.

Jim

On Mar 12, 6:17 pm, "Travis Marlatte"
wrote:
"RST Engineering" wrote in message

...

A coup'la questions & comments:

1. Why would you disconnect the battery to replace the alternator?

I suspect it was in an attempt to reseat all connections that could
contribute to the problem. I had already done this as well as "moving" all
of the alternator mounting bolts. I didn't try any magic juice, however.



2. One presumes certain basic troubleshooting procedures prior to
throwing parts at the problem, like back all heavy nuts grounding the
alternator, squirt in a little magic juice, and retighten.

I'll emphasize that I did my own diagnosis and concluded that it was an open
diode. I took it to the shop not to have them diagnose but to swap the
alternator - which they did quite well and it (or the process of doing it)
solved the problem.

-------------------------------
Travis
Lake N3094P
PWK

We once had an alternator whine in a 172. The alternator
wasn't the problem; there was a ground loop somewhere. After messing
endlessly with ground straps and filters and other connections, I
finally got fed up and ran the alternator using our table saw motor--
wheeled the saw up to the front of the airplane and used the belt to
spin the alternator while I got under the panel wearing the headset
and used a jumper to try grounding/ungrounding various jack points.
Managed to minimize the whine by moving a groundpoint to a point where
a bunch of other avionics grounded. Old airframes develop resistances
at riveted joints, causing a voltage drop across certain components
and introducing noise that's supposed to be filtered out in the radios
or audio panel. I think. Anyway, it worked.

Dan