Attn: Tibur Waltson

Yes, you can use the car as a charging system load along with a dc
voltmeter, however it is only as good as the battery's percentage state of
charge (ie 70% or higher), temperature and being a good battery. If the
battery is discharged or bad or cold engine your test will be erroneous.

Remember, with a battery charger you are replenishing the expired portion of
the reserve capacity.

An alternator is not a battery charger and can limit its output if the
battery is discharged.

In order to get both the 2000 and the 750 rpm voltages to increase, you may
need to charge the battery with a battery charger to at least 70% state of
charge or a hydrometer test 1.245 specific gravity.

Also, when retesting with a voltmeter, a reasonably tight alternator drive
belt, and a good known battery, only turn on the headlights, AC, and radio
that would simulate about a 40 to 45 amp accessory load. You should observe
about 14.2 to 14.5 volts d.c. at a 2000 rpm fast idle.

Think of summer night driving whether you are driving at 60 mph (ie 2000
rpm) or stopped at curb idle (ie 750 rpm) and waiting for a traffic light to
change to green.

This really is not rocket science.







"Tibur Waltson" <Toush@hi.com> wrote in message
news:3c6ef977c6e834d280c29ce6a4a2aa8b@news.bubbane ws.com...
> Today I load test the alternator by an instruction in an aftermarket
repair
> manual. The instructions says to turn on headlights, defoggers, fan,
radios,
> cigarrete lighter, etc and measure the voltages. It reads 13.6V at 2000
rpm
> or 11.2V at 750 rpm. It's within normal range according to the book. But
the
> headlight seems a bit weak unless rpm is above 1300 rpm or sometimes it
just
> too weak for the starter. We hardly drive in the highway. It has an alarm
> system. Is the alternator fine?
> TIA
> Tibur
>
>
>
>
>
>


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