Re: 2000 Toyota Sienna Alternator/Regulator

On Jun 8, 4:50 pm, Ken <n3k...@xxxxxxxxx> wrote:
On Jun 8, 10:07 am, Retired VIP <jackj.extradots....@xxxxxxxxxxxxxx>
wrote:



On Sun, 07 Jun 2009 16:17:35 -0400, Hachiroku ???? <Tru...@xxxxxxx>
wrote:

On Sun, 07 Jun 2009 12:41:47 -0700, Ken wrote:

Are your running the air conditioner?

Yes I said that the air conditioner was running in all the above cases
to keep things constant.

Ah, yes...so you did.

Difference in fan speed?

11.8 to 12 is actually normal operating voltage. You don't want to go
below this.

12.8-13.8 is full voltage with no options running. It's not uncommon for a
car (esp Toyota) to drop to ~12VDC when running in the summer with fans,
etc running.

I'd get nervous below ~11V, though.

Also, get an ammeter. It's a better indicator of what's going on. If it's
above zero, you're ok. If it's below...

I beieve they are called galvanomters, or "charge meter" for your FLAPS.
Need to keep it simple for those guys, sometimes. Some of the AutoZone
guys might even know what a car is!

Someone has giving you some bad information Mr. Hachiroku.  There are
two charge voltages for lead-acid batteries.  The lower value runs
from 13.2 to 13.8 volts and is called the "Float" level.  The higher
value runs from 13.8 to 14.4 volts and is called the "Equalize" level.
The normal open circuit voltage of a fully charged battery is 12.6
volts.  These voltage levels are for a battery temperature of 70
degrees F.  Cooler temps will result in higher required voltages to
acheve the same results (except for the open circuit voltage - that
stays the same).

Float charge is for a long-term maintenance charge.  It minimizes
water loss but at the lower voltages (>13.6v) will not fully recharge
a battery in any reasonable amount of time.

Equalize is used to fully charge a battery in a short period of time.
It increases water loss but will return a battery to a fully-charged
state.

Cars use the equalize levels and the battery voltage of a running car
should always be higher than 13.6 - 13.8 volts unless the alternator
is unable to supply enough current for the load.  But it should
recover pretty fast when engine RPMs increase above an idle.

Given the info from the OP, I'd guess that one of the diodes in the
alternator is bad.

Jack j

Thanks Jack j,
There is a slight whine coming out of the alternator and I've heard
before (probably old wives tale!) that this can indicate bad diodes.
So the obvious question would be are these internal and therefore the
alternator needs to be replaced or are they accessible? How can I test
this or would this show up using an alternator tester? Thanks again
for the help.

Ken

By the way, I am also getting a very slight flickering in the lights
(most noticeable in the dome lights). I have never seen this on a car
before, but do see it on the Sienna. I had posted previously on this
and everyone convinced me this is normal. I was wondering in the past
if it might have been from a diode problem letting an AC component
into the electrical system (which the battery acting as a big
capacitor will buffer).

As to the post about the specific gravity on the new battery, it is
sealed. Yea I know, bad idea, but I got it at a great price.
.

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