Weird charging problem in 4kq - Solved, partially

[Luis Felipe Patiño]

It is, of course, the slip rings (commutator) of the alternator
shaft being too deeply grooved, too worn.

Yes, Avi, the brushes sure make better contact on a grooved (concave) ring,
a good thing if the rings
are only moderately worn.

However, if the ring are grooved as deeply as mine, the contatct becomes
_too_ good, increasing friction so much
that one or both brushes get pushed tangentially to shaft
rotation when the engine reaches a certain speed, or
change in speed. (They can be pushed back because they
have quite a bit of play inside the brush-holder assembly
of the voltage regulator, plus since they are allowed to
extend farther than normal by the concave trough, the brushes are already
farther out of their holders,
which makes the play even worse.)

As the brush gets pushed back, it then loses contact area
with the ring, rapidly decreasing current to the field -- and
charge to the car -- even ceasing it altogether (and
causing the OXS and ALT lights to faintly flicker in
the dash and the volt meter to sink).

Only when the engine revs down enough, does the ring
friction decrease enough to allow the brush to come
back to its normal full-contact position restoring the
field current and alternator charge.

All that friction wears the brushes much faster than
normal. When worn enough, the play allows the friction
to _tear_ one of the brushes by its wire from the soldered
joint, finishing off that set of brushes.

At the moment, my alt has a nifty NAPA Echlin 'merican-
made regulator, which I've been nursing by keeping
the revs under 3000 as much as possible, and so far
has lasted me a month.

(BTW NAPA has the brushes for $6, Echlin number E455,
and an alternator that supposedly fits the '87 4kq for $110
w/lifetime guarantee.)

But the reality is that I need new rings or a remanufactured
alt. I thought of patching a regulator with epoxy putty to
lenghten the brush holders and reduce play, but honestly,
I've been cutting too many corners with this car, and with
my life in general, making miracles with cents.

What I really need is a job. That's what I need help
with. Could some kind lister help?

My work history/education is interesting, but off-topic and WOBW, so please
look instead at the following page that
you might enjoy

http://genius.ucsd.edu/~lpat/findit/math.html

then please email me privately for further details.

TIA,

Luis P

(And thanks to Bob from AudiSport for first giving me the
correct clue to the charging problem, to Paul Cole for
teaching me how to discover and eliminate other causes,
to Huw Powell for his corroboration and awesome page
on alternators, to Bernie Strub for showing me a
way to fit an older alt in my '87, to Avi Meron for inspiring
me on how to get my geriatric alt back to life for
pennies, and Tom Love, Tony Lum and all of you who
helped keep my 4kq running.  And apologies to Mike F,
for being so broke that I couldn't afford his alternator.)