Chris asks:
> Is there any way to check to see if my alternator is charging without taking
> it off and into the parts store?
Here in CA, Kragen will take a portable tester out to your car in the
lot, and test it in-place. But if you're like me, you won't let them near
your car :-)
Does your ammeter work? If so, you should see it go slightly negative
with engine off and headlights on. Start the car and it should go
positive. That shows if the charging system is pushing energy back
into the battery.
Do you have a voltmeter? Stick it across the battery terminals, engine
off. Should read about 13 volts with a fully charged battery and no
load (12.6-13.2). Start the car. The voltage should now be HIGHER
than it was. If not, rev the car to 2000 rpm or so and see if that does
it. If no increase: bad regulator, alternator, or connection somewhere
(what, corroded connections after only 30 years?). If increase only
at higher revs - weak alternator; could still be wiring or regulator (not
enough power to the rotor winding).
No test equipment? This evening, turn on the headlights. Note relative
brightness. Start the car. Are they a bit brighter? Rev the engine. Did
they brighten? (hint: higher voltage = brighter lights)
If everything looks OK, I'd start hunting for a current drain when the
car is turned off. Pull a battery cable, pop a turn signal light and use
it as a 'test instrument' - touch the base to the battery post and the
battery cable to one of the pins on the bottom. If the filament glows
at all, something is pulling current (digital radios shouldn't pull enough
to be noticeable). If no glow, leave it disconnected overnight. If the
battery is now dead, it's gotta be an internal flaw in the battery.
Do NOT run the car with the battery disconnected. In the unlikely event
there is a flaw in the regulator and it allows the alternator voltage to
rise too high, the battery will act as a 'sink' and stabilize the voltage
(the battery will also cook itself to death - hmmm...). Pop the battery,
and if the voltage zooms, it's bad news for anything electrical.
-- John
John F Sandhoff sandhoff@csus.edu Sacramento, CA
|