Charging Question (Electrical - Not Credit)

Michael Bremer wrote:
: When I turn on the light the meter rises. It appears to be a stock meter
: that doesn't have a lot of numbers, basically "0" on the left, "30" in the
: center and "60" on the right. If I extrapolate/interpolate/guesstimate the

If indeed the meter reads these values, there is likely an AD against it.
IIRC, the 0-60 Amp Loadmeters that were OK had a little white dot by the
number "60". The ad is AD-86-17-01. I found that it had not been done on
my airplane. The new loadmeter kit from Piper (PN 765-186) reads "0 35 70"
although the alternator is still rated at 60A.

I don't think that the AD is related to your problem, as it addresses
the meter connections. The original meter is in series with the alternator
output, which means that the 60A goes through the meter and a couple hefty
bolts on the back of the instrument panel. The new meter is a shunt type,
with about 6 feet of #2 wire for the shunt and 2 skinny wires (#20?)
connecting to the meter itself.

My old meter was sticking in cold weather. It would always indicate "0"
no matter what when the temp was below freezing. I have heard of this
happening in other Cherokees: the amp meter reads low in the winter. I don't
think this is your problem either.

I would guess that either the regulator is sticking or failed, or the starter
is hanging up (as I said earlier). The starter is easy to check, to check
the regulator measure the voltage somewhere convienient like the cig. lighter.
If the voltage stays about the same with different engine speeds and loads,
the regulator is probably OK.

Please let us (me) know what you find out!
--
Aaron Coolidge (N9367J)

Michael Bremer wrote:

Looking for some opinions and I know that there are no shortage of those
here.

I just returned from a little night ride to get my three landings and
noticed what appears to be an abnormal reading from the ammeter.

When on the ground, preparing for takeoff, I see a significant rise on the
ammeter when I switch the landing light and fuel pump on. I know that this
is normal, particularly with the landing light drawing a good bit of juice.

The question is...When applying full engine power for takeoff, the ammeter
rose off the scale. Not a sudden pop of the needle, but a pronounced rise
as the RPM went up. When throttling back to cruise power, the meter drops
to a more normal reading?

I'd say it's seems like a fairly flat battery being charged.
How long was it since that A/C was flown for a reasonable
amount of time ?
All batteries self-discharge at various rates depending upon
their chemistry.

MC wrote in message ...
Michael Bremer wrote:

Looking for some opinions and I know that there are no shortage of those
here.

I just returned from a little night ride to get my three landings and
noticed what appears to be an abnormal reading from the ammeter.

When on the ground, preparing for takeoff, I see a significant rise on the
ammeter when I switch the landing light and fuel pump on. I know that this
is normal, particularly with the landing light drawing a good bit of juice.

The question is...When applying full engine power for takeoff, the ammeter
rose off the scale. Not a sudden pop of the needle, but a pronounced rise
as the RPM went up. When throttling back to cruise power, the meter drops
to a more normal reading?

I'd say it's seems like a fairly flat battery being charged.
How long was it since that A/C was flown for a reasonable
amount of time ?
All batteries self-discharge at various rates depending upon
their chemistry.


Batteries tend to sulphate as they age. The lead sulphate that
forms on the plates as a result of normal discharge is usually
converted back into acid during charge, but a small amount always
remains, and if the battery is left in a low state for any length of
time, the sulphate becomes more permanent. Eventually it breaks off
and piles up in the bottom of the cells, shorting them a bit and
causing a huge charge rate.
Best bet is to try another battery. If the regulator was shot,
the lights would get much brighter as RPM came up.

Dan

I just checked my records. The battery was last replaced 4 years ago. The
plane flies about 40-50 hours a year.


"Michael Bremer" wrote in message
ink.net...
Looking for some opinions and I know that there are no shortage of those
here.

I just returned from a little night ride to get my three landings and
noticed what appears to be an abnormal reading from the ammeter.

When on the ground, preparing for takeoff, I see a significant rise on the
ammeter when I switch the landing light and fuel pump on. I know that
this
is normal, particularly with the landing light drawing a good bit of
juice.

The question is...When applying full engine power for takeoff, the ammeter
rose off the scale. Not a sudden pop of the needle, but a pronounced rise
as the RPM went up. When throttling back to cruise power, the meter drops
to a more normal reading?

Opinions???

Thanks

Mike

Michael Bremer wrote:
: The question is...When applying full engine power for takeoff, the ammeter
: rose off the scale. Not a sudden pop of the needle, but a pronounced rise
: as the RPM went up. When throttling back to cruise power, the meter drops
: to a more normal reading?

Is the starter stuck? If the started bendix is hanging out it'll draw
lots of amps, burn up in short order, and wreck the flywheel ring gear.

PS, I also fly a 1968 PA-28-180 well equipped with lots of electrical stuff
and I can't get over 35-40 A with everything turned on.

PPS, most alternators can provide rated output at "idle" RPM, thus their
advantage over generators. I don't idle my plane at the idle stop, I use
800 to 1000 RPM for better lead scavanging and less vibration.
--
Aaron Coolidge (N9376J)

We had a similar problem on our Archer a few years ago. The ampmeter in the
Archer is actually a voltmeter, reading the voltage across a length of wire
in series with the alternator output. On our plane the wire loop is strapped
to the engine mount. the wire connections can gets weathered, and get a
little corroded, and asa result of the corrosion the voltage drop increases,
which the ampmeter reads as increased alternator output. Cleaning the
connections on the ampmeter shunt wire has always restored the readings to
what appear to be resonable numbers. How do you tell?

If the landing light or pitot heat are rated at 100 watts, look for around
an 8 amp rise in alt output when you switch each consumer on. If the metered
rise is higher than the load you've added (which is specified in your POH)
the the meter calibration is off and should be corrected, usually by fixing
the shunt connections.

Cheers,

Jerry
"Michael Bremer" wrote in message
ink.net...
Looking for some opinions and I know that there are no shortage of those
here.

I just returned from a little night ride to get my three landings and
noticed what appears to be an abnormal reading from the ammeter.

When on the ground, preparing for takeoff, I see a significant rise on the
ammeter when I switch the landing light and fuel pump on. I know that
this
is normal, particularly with the landing light drawing a good bit of
juice.

The question is...When applying full engine power for takeoff, the ammeter
rose off the scale. Not a sudden pop of the needle, but a pronounced rise
as the RPM went up. When throttling back to cruise power, the meter drops
to a more normal reading?

Opinions???

Thanks

Mike