Car wouldn't start (an old '92 Subaru Legacy L wagon). Battery is about
3 years old and the car started a week ago. However, today it just
cranked like one turn and died. I can hear the relay click as I turn
the key but the engine doesn't budge. I also noticed the electric seat
belt moved slowly.
I popped the hood, jumped started from my other car, and with a
voltmeter measured across the battery. It measured 12.5V. As I recall,
each cell in a new battery should be 2.2 volts and there are 6 cells so
a new battery should measure 13.2 volts, so 12.5V isn't bad for a
middle-aged battery. However, I expected the voltage to be higher while
the car was running due to the output from the alternator. The voltage
also did not fluctuate when I revved the engine. It dropped a volt when
I turned on the headlights. So it looks like the alternator is bad.
While 16 years old, mileage is only 135K so, on average, the 2
alternators have lasted only about 67K which seems a bit short-lived
(actually the first one probably lasted 105K and the 2nd died after
I had to replace this alternator about 4 years ago. The prior run
burned up. Its bearing went bad and it heated up so you could smell the
varnish on the windings within a few blocks of driving from cold. It
was a rebuilt and is now out of warranty. I got it for around $80. The
salvage place doesn't have another alternator (except for a
retail-priced new one). I can get one for $118 at PepBoys with a
lifetime warranty; however, I'm wondering if just the voltage regulator
is shot. I can't see what the module is on the outside so maybe the
regulator is inside. If inside, I'm not dismantling it to replace that
module. I suspect if it is inside that it'll be riveted and positioned
where it won't be easy to get out to replace it, assuming that just the
regulator can be purchased and is much cheaper. If the voltage doesn't
get above what the battery alone will provide, is it even a voltage
I can't find my battery charger so I'll call a buddy to drop by with
his. I need to charge the battery so I can get to PepBoys to have them
do an alternator test and have enough juice in the battery to start it
again to get the old Subie back home.
What should be the voltage across the battery while the car is running
and with a working alternator? I thought it was 14.4V. It would have
to be higher than the 13.2V for a new battery.
Is the voltage regulator inside or outside?
How trustworthy are these parts shop alternator testers?
Suggestions on how to go cheap on the alternator replacement? The
1-year salvaged rebuilt alternator lasted 4 years. Considering it was a
third the price, another 4 years is just fine with me.