Electrical System Question for 64 T-Bird

64bird wrote:

> Thanks again. Also not trusting of chain store products, I took dead
> battery back to the store to get tested. I wanted to be 100% sure that
> I had a good battery before I start changing electrical parts. Again
> the battery was acting weird and they gave me a new one, this time, a
> better brand with more power. Made a huge difference in crank speed.
>
> I drove the car with the brand new battery and again, the ammeter would
> goes way off to "C" when I accelerated. So this symptom is not caused
> by running off a near dead battery.
>
> I did the negative cable test, and sure enough, very small sparks occur
> when I take off and put on the cable.
>
> I've never heard of diodes. Would these be easy for me to find and
> replace?
>

Next step - disconnect the big wire going to the back of the alternator
and try the negative cable thing again. If no sparks/ammeter movement
then I'll bet that the problem is one or more diodes.

The diodes are inside the alternator case, there should be six of them.
I don't know how hard they are to replace on your design of
alternator. What they do is they take the AC current that the
alternator produces and rectify it into DC (a diode is kind of a "one
way" valve for electricity) Again, if you don't do your own work I
would take both the alternator and the regulator in to a shop as a pair
so they can adjust/check the regulator as well.

Incidentally, to keep from killing one or more batteries I would leave
the neg. cable disconnected when not using the car until this issue is
fixed.

good luck

nate

--
replace "fly" with "com" to reply.
http://home.comcast.net/~njnagel

"Daniel J. Stern" wrote:

> > Ummm... correct me if I'm smoking too much crack again, but isn't the
> > problem you describe pretty much unique to a generator system?
>
> Yes. There is no way that a sticking *alternator* voltage regulator can
> drain the battery.

Why not? Doesn't the regulator control the current to the
rotor coils? If somehow the requlator continued to power
these coils, wouldn't it drain the battery in the same
manner as if the regulator continued to power the feild
coils of a generator? I know it is not as likely as for a
generator, but is there not some failure mode of a regulator
that could cause this problem?

Ed

The amp gauge tells whether current is flowing into the battery, or
C(harging) it, or out of the battery, D(ischarging) it. In other
words, under circumstances when the alternator or generator can't
provide enough power to run whatever is turned on, the battery makes up
the deficit.

Now, one of several reasons for quitting generators and moving to
alternators was better output at low rpm, so that you would be less
likely to slowly discharge the battery when, say, sitting in heavy
traffic with your lights and defroster and so forth going. (I've
always read that the T-bird got alternators in 1963, although Ford in
that era was the king of ill-documented running changes, and generators
were still in use in some of their other models well into '64, so who
knows.) Anyway, with the engine idling, an alternator system should
about break even or, at worst, sag a little toward the "D" side.

The radical swing toward "C" when you pick up the revs means that
voltage is suddenly available and is being dumped into a starved
battery.

(A sidelight on what you're measuring and how: The 64 and 65 Birds,
if I've got this right, had full-flow ammeters. The '66 gauge just
samples the flow and is notorious for having about a 1/8 inch range of
indication when it works at all, after lo these many years. )


Anyway, when an alternator isn't delivering on its supposed key
advantage of providing decent power (manifested as voltage greater than
that of the battery) even at low rpm, there's probably something wrong
inside it, like a shorted diode. (Do you hear radio whine that varies
with rpm?)

See for instance
http://www.allpar.com/eek/alternators.html
http://autorepair.about.com/cs/elect.../aa122700a.htm

The shop manual for the T-bird gives instructions for rebuilding the
alternator and for adjusting the voltage regulator as well; or you
could just replace the alternator and, for inexpensive prudence, the
regulator.

The T-bird specialty houses have an electronic regulator that uses the
same mounting holes and electrical connections as the old-fashioned
kind, which I guess you can keep around in case you or a future buyer
cares about concours points. You can find them at
http://www.tbird.org

While you're going through it, pay special attention to whether the
connections are clean and solid, especially the grounds, source of much
heartache on these old cars.

Cheers,
--Joe

Ad absurdum per aspera wrote:

> The amp gauge tells whether current is flowing into the battery, or
> C(harging) it, or out of the battery, D(ischarging) it. In other
> words, under circumstances when the alternator or generator can't
> provide enough power to run whatever is turned on, the battery makes up
> the deficit.
>
> Now, one of several reasons for quitting generators and moving to
> alternators was better output at low rpm, so that you would be less
> likely to slowly discharge the battery when, say, sitting in heavy
> traffic with your lights and defroster and so forth going. (I've
> always read that the T-bird got alternators in 1963, although Ford in
> that era was the king of ill-documented running changes, and generators
> were still in use in some of their other models well into '64, so who
> knows.) Anyway, with the engine idling, an alternator system should
> about break even or, at worst, sag a little toward the "D" side.
>
> The radical swing toward "C" when you pick up the revs means that
> voltage is suddenly available and is being dumped into a starved
> battery.
>
> (A sidelight on what you're measuring and how: The 64 and 65 Birds,
> if I've got this right, had full-flow ammeters. The '66 gauge just
> samples the flow and is notorious for having about a 1/8 inch range of
> indication when it works at all, after lo these many years. )
>
>
> Anyway, when an alternator isn't delivering on its supposed key
> advantage of providing decent power (manifested as voltage greater than
> that of the battery) even at low rpm, there's probably something wrong
> inside it, like a shorted diode. (Do you hear radio whine that varies
> with rpm?)
>
> See for instance
> http://www.allpar.com/eek/alternators.html
> http://autorepair.about.com/cs/elect.../aa122700a.htm
>
> The shop manual for the T-bird gives instructions for rebuilding the
> alternator and for adjusting the voltage regulator as well; or you
> could just replace the alternator and, for inexpensive prudence, the
> regulator.
>
> The T-bird specialty houses have an electronic regulator that uses the
> same mounting holes and electrical connections as the old-fashioned
> kind, which I guess you can keep around in case you or a future buyer
> cares about concours points. You can find them at
> http://www.tbird.org
>
> While you're going through it, pay special attention to whether the
> connections are clean and solid, especially the grounds, source of much
> heartache on these old cars.
>
> Cheers,
> --Joe
>

yeah I forgot to mention that, if there is not a wire in the wiring
harness connecting the regulator ground to the case of the alternator,
consider adding one.

nate

--
replace "fly" with "com" to reply.
http://home.comcast.net/~njnagel

I disconnected the alternator and there were no more sparks. So I know
the problem lies in the alternator or something that is connected to
the alternator. I took out the alternator and had it tested at Kragen
(because they're the only guys open Sunday) and they said the
alternator was good. I took out the regulator too but they couldn't
test it. I'm going to take both parts to a specialty shop tomorrow.

If the alternator is ok, and assuming all my wires are proper, what
else could be causing the battery drain when the car is off? Could the
regulator be the culprit for all these problems?

Thanks to all the help from all the posters!!!!

64bird wrote:

> I disconnected the alternator and there were no more sparks. So I know
> the problem lies in the alternator or something that is connected to
> the alternator. I took out the alternator and had it tested at Kragen
> (because they're the only guys open Sunday) and they said the
> alternator was good. I took out the regulator too but they couldn't
> test it. I'm going to take both parts to a specialty shop tomorrow.
>
> If the alternator is ok, and assuming all my wires are proper, what
> else could be causing the battery drain when the car is off? Could the
> regulator be the culprit for all these problems?
>
> Thanks to all the help from all the posters!!!!
>

Keep us posted, my money is still on a bad diode but we'll see. If you
have no spark/current with the alternator out, the problem is definitely
in the charging system somewhere. I think you are close to a solution here.

good luck

nate

--
replace "fly" with "com" to reply.
http://home.comcast.net/~njnagel

Hi Nate,

I took the parts to an electrical shop and the guy told me he can't do
any tests without the car. I got impatient and decided to spend $50
and change the alternator and regulator, and I did.

With the newly installed parts, the good news is I don't get any sparks
on the negative terminal with the car off. But the ammeter is still
acting weird, but not the same way as before. When I drive with the
lights on, the ammeter goes towards "discharge" and stays there for a
while. Then, all of the sudden, it will shoot to the right and charge
the battery depending on how much gas I give it. It will charge for a
few seconds then it's back to the discharge area. Could this be
normal? Could this be the way this cars' charging system is supposed
to work? i.e., discharge to a certain point then charge back up and so
forth?

Thanks

That could easily be describing a polished up fan belt. My V belt
engine acts that way when I kill my belts.

I test them by taking a cold off engine and seeing if I can hand slip
the alternator pulley in the belt. The alternator takes a few HP to
spin up and if it can be hand slipped it will slip under load.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

64bird wrote:
>
> Hi Nate,
>
> I took the parts to an electrical shop and the guy told me he can't do
> any tests without the car. I got impatient and decided to spend $50
> and change the alternator and regulator, and I did.
>
> With the newly installed parts, the good news is I don't get any sparks
> on the negative terminal with the car off. But the ammeter is still
> acting weird, but not the same way as before. When I drive with the
> lights on, the ammeter goes towards "discharge" and stays there for a
> while. Then, all of the sudden, it will shoot to the right and charge
> the battery depending on how much gas I give it. It will charge for a
> few seconds then it's back to the discharge area. Could this be
> normal? Could this be the way this cars' charging system is supposed
> to work? i.e., discharge to a certain point then charge back up and so
> forth?
>
> Thanks