Thanks. I put in a good battery and it starts right up. I notice that
the fan switch is stuck on and the fan is running continuously
when the car is running. I have disconnected that for now.
It idles but the rpm bounces up and down. When the rpm
bounces up the volts go to 16V, when the rpm bounces
down the voltage goes to 12V.
I raced the motor and the belt squeaks so I added some anti-
squeak compound. I charge up the old battery for 2 hours and
put it in the car and it starts right up and drivable. The voltage
now reads 12 volts at idle and 13 volt steady at 2000 rpm. The
alternator is a year old. I now think either the fan killed the
battery or the alternator didn't charge. What is the next
Sounds like you need a new alternator or regulator (if the regulator
isn't part of the alternator.) 13V is just barely enough to hold
steady, you are slowly draining your battery. With the engine running
you should be seeing a *minimum* of 13.7V at all times. The idle
weirdness may be due to the low voltage and/or the fact that the
battery was disconnected. Worry about it only if it's still weird
after fixing the voltage problem.
Sounds like your alternator was not charging the battery and the battery
used up all is juice. Most times you can disconnect a pos or neg cable and
the vehicle will run of the alternator alone ( not recommended for along
time) as the alternator might be putting out full output which might damage
Thanks everyone. Turns out the altenater is dead.
I charge up the battery again and I put a voltmeter on the alernator
output and it reads 10 Volts. So I disconnected the battery terminal for a
second (like you said since it will not go above 11V no matter how hard I
rev) and the engine stalls. The (Autozone) alternator is only a year old, I/m
not sure what can destroy it. Maybe the sticky fan switch detroyed the
I know a guy that went thru 3 auto zone alternators...........after
returning the last of the 3 so called "lifetime" alternators due to the
shaft locking up, AutoZone gave him is money back for it and said go some
place else.......they didn't want to see him any more. they quoted him a
policy for refund after 3 warranty's, wont try to help him any more.
they always miss box stuff, miss labeled stuff, and in the case of my 86
lebaron, gave me a 3 port heater control valve ( ports for 3 hoses) and said
that it "superseded" my current 4 hose valve. when I asked what they that I
should do with the 4th hose, I got dumb stares........
go to another parts place. borrow AutoZone's tools and test instruments but
go elsewhere for parts.
There are many things that can kill an alternator. The sticky fan
switch won't directly kill the alternator. What can happen, though, is
the switch gets stuck and runs the battery down ... not enough so the
car won't start but enough so the alternator has to work really hard to
get the battery voltage back up. That extra work done enough times can
kill the alternator.
Also, if the battery is in a state of discharge and will not accept a
charge, the alternator will work really hard trying to charge a dead
battery ... bye bye alternator.
If you bought a poor quality rebuild, that could do it, too. I used to
rebuild alternators for a living. I found that many people didn't want
to pay the price for a good quality rebuild (new diodes, new regulator
(if applicable), new bearings, etc) because it was expensive and the
major parts stores were virtually giving the whole unit away (and a
person didn't have to wait for it most of the time).
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