Having problem with battery or Alternator.
97 626 V6 111,000 miles on original alternator.
It is on it's second battery. A Duralast 7 year
that is 4 years old. Serpantine Belt look good
and tension appears ok.

No Alternator light warning. This should indicate
the output, diodes and regulator are ok, that
is if the light works as it should.

I Put the battery on a charger and it would not draw anything.
Does this not indicate a short?

Once we jump it and get the engine running my
voltmeter reads right on spec. between idle and
2500 rpm. I have no way to test the amps.

I also have not done a hydrometer test on the battery yet.

Once the car gets a jump and starts it will run for awhile
but then it will eventually die especially if you turn on
the headlamps. This indicates to me the problem is the
alternator. But...could be a short in the battery perhaps?

In older cars I just started it up and removed the
positive cable and if the engine kept running that
meant the alternator was good. Simple.
With these newer cars I am told that procedure can
damage the alternator. Is this true?

I suspect that if there is a plate that eroded and
there is a short between 2 cells that could prevent the
alternator from sending enough amps to the electrical
system to keep things going. I have heard of this
but have never had it happen to me.

I want to avoid taking that alternator out of that
626 because is going to be a pain just as it is on
my 323. Looks like the AC compressor has to come
off first then the alternator. I could be wrong because
I have not looked at it that close yet.

I would also hate to buy and alternator I don't
need or a battery.

I would just go get a new battery and alternator
and belt if Mazda did not want damn near 400.00 for one.
I refuse to buy a reconditioned because I do not
enjoy removing altenators from cars every 6 months.
I bought 3 reconditioned altenators for my 87 323
in 1 year before I asked for a full refund and bit the
bullet and paid 270.00 for a new one at the dealer.
It's been on the car now for 170k no with problems.
You get what you pay for.

Any feedback is greatly appreciated. I am usually
very good at troubleshooting battery vs alternator
but this is a new situation for me.

I am betting it is a short in the battery.

Or perhaps the regulator is getting hot over time
and boiling the battery thus causing the amps to
drop.

Thanks for your advice. I am an old school shade tree
mechanic and seem to always need help with these
new cars. This forumn saved my butt on new halfshafts
I and really aprreciated the advice.

Kloyless@swbell.net

Took the battery and put it in another car.
Problem followed the battery.
It was stupid of me to even post
before I at least tried that.

First time I have ever seen a battery
do that.