Check battery light goes ON

[MartinS]

Hi,

Is the alternator interchangable with another engine?

92+ COROLLA 1.6 XLI COMPACT
86' COROLLA 1300 DL COMPACT

Anyone?

[mc68]

you know the way to check voltage output of an alternator is to put +ve of the voltmeter on the ht lead of the alternator, and earth to the chassis.

it should be at least 14.3/14.4 volts

[jondee86]

Quote:Is the alternator interchangable with another engine?

When my alternator died recently, I took a walk thru the local
wreckers yard, and found similar units on many of the older Toyotas.
The only difference when you take one from a FWD car, is that bolted
terminal will end up in a slightly awkward place underneath.

The round plug seems to be interchangeable on just about all of
the older models. And the 5-groove pulley is also very common.
There are two variations in the width of the "lug" that bolts to the
block; a wide version and a narrow version. You want the wide one.

I finished up taking one from some random old FWD Corona, and it
worked fine. Getting the wire to the teminal was a bit of a stretch, and
the pulley was actually slightly smaller than the AE86 one. This means
I am at the end of the adjustment with the standard belt.

Hey, but for NZ$35 it is about 10% the price of a new one

Cheers... jondee86

[Euripides]

It is the alternator, but there's no need for replacement.
I had the same symptoms to mine recently.
Replace only the contacts (don't know the excact name in English, brushes maybe...). The 2 small cylinders inside the alternator. They worn and became short after years.
Very cheap.
Check it!

[dikolotour]

It is the alternator for sure. I had the same symptoms... Just like Euripides said you have only to replace these two small things. We call them coals they are like the stone of a lighter and they are worn with the usage...

:wink:

[MartinS]

Changed the alternator the other day, now everything is fine.
thx

[max_ae86]

I have a strange problem, the warning charging light lit at high revs, at 5k and up. During idle it stays off. The voltage was 14,2 -14,3V even at high revs so I guess the alternator is fine (it has been rebuild 3 years ago). What can it be? I suspect a bad connection may be the problem but still the voltage is good, just don't know where to look?

[jondee86]

Had the same problem myself... charge light came on at high rpm, but
off at lower rpm. Turns out that the AE86 monitors for over-voltage as
well as under-voltage. Cause was a bad diode in the rectifier section
allowing AC to leak thru into the DC section.

I think you test by using a multimeter set to AC to read the battery
voltage when the engine is running. If you see AC voltage that is the
problem... but pay you to check that is the correct test before you take
a chance with an expensive meter :-P

Cheers... jondee86

[max_ae86]

I just checked AC voltage is 31-32V, but this is the same voltage as I measured on my other car which is perfectly fine. So I'll have to dig more into it. Thx for advice.

[jondee86]

Perhaps I did not explain this correctly. The alternator creates an AC output
which is rectified to DC for charging the battery. You should not be able to
read any AC voltage on the DC output circuit.

If you have AC voltage on the DC side, it is because a faulty diode is letting
some AC voltage pass through the bridge rectifier. This AC voltage is then
superimposed on the DC voltage, to raise the output voltage high enough to
light the charge light.

Hope that makes it clearer

Cheers... jondee86