alt or battery

[Kim K Kaiser]

having just done the ac system,

seems my batter y or alternator may be going out,, 

at off    battery is at about 11.8   while running, doesnt get to about but 12.5 on the meter.  11.8 doesnt seem to give it enought juice to start, so it just cliccks,, i put a battery booster on , fires right up,,

it doesnt get to the 14.9 or so while engine is on.  so, hte question is, is it batter or alternator?

battery is about 2.5 years old, if that matters.

secondly,  would the additionl of the compressor belt to the engine have any effect on the alternator ? would that addition to the spinning have any effects on any other systems.  I havent run the ac but once, since i completed it, and just enought to see if it was cold air,, its only about 45 here for a high right now.

just wondering if there would be any addiitonal drain on the alternator now that ac is hooked up.

[Kim K Kaiser]

Its stick except radio added w one of those power converters that carries th speaker load.  Iglad to kno ac not a drain.  I got one of those high eficiency units,to avoid excess loads on engine.   Ck into the battery testr tomoro.  Thanks

[Kim K Kaiser]

Well definely not get 14 at idle.  Not even close.  11.7 w engine off

[Jason Edge]

An easy way to check a battery is to disconnect everything, fully charge it with a battery charger and come back the next day and take a voltage reading. It should be somewhere between 12.4 and 12.8 volts.  Leave it a week or two and you might see 12.3 as a bit of the voltage disappates. The old school way to check an alternator with factory wiring with external voltage regulator is to crank car, turn off the electronics (e.g. lights, etc) and disconnect a battery cable just long enough to see if the car keeps running off the alternator's current. If it immediately dies, then the alternator is bad. With the car running and electronics turned off, you should see something between 13.7 and 14.7 volts. The voltage is regulated by the alternator of course, and it could be the faulty and the internal voltage relay may be cutting out before it's intended voltage limit. Voltage regulatores are cheap enough (last time I checked) and would suggest a new one if never replaced. Also make sure all connections from alternator to battery and regulator are tight and alternator is well grounded via the one ground wire with loop connector.
Back to the battery I  have not cranked my 64 Coupe de Ville in 2 weeks and just did a test and it is 12.36 volts. I have a bench battery that I used for testing radios, etc. and have not probaby charged it in 3 or more weeks and it is still at 12.3 volts.  If the battery is bad and you give it a charge and come back the next day and take a reading and it has dropped way down you know it is bad.  You can buy testers to do load testing but this has always worked for me.

[Kim K Kaiser]

Well, indid the old svhool ck.  Got battery charged to 12.7 w enine off.  Cranked it up, pulled the black cable off, died immediately.  As back up, hooked back up , started,  checked w meter w everything off. Wont go over 12.7,  not even close to 13.  So, sounds like alternator.

Is there a recommeded part from the part stores? Do they fit w current wiring in car or will i hv to figure out how to re wire?

[Jason Edge]

I just tested my 64 CDV... It was as stated 12.3 volts. cranked it up, got a voltage of about 13.8 volt running then disconnect + bat cable and it jumped up to 14.6 volts which makes sense as it is not charging the battery at that point and is soley running off the alternator. As battery charges up a bit, it should get a bit higher running voltage reading, but 13.8 was fine. I also disconnected 1st the Pos battery cable and then the Neg battery cable just for my sanity.. as I usually just remove the pos cable but as long as the alternator is ground which it is, it should not matter which battery cable you remove,, which it didn't.

With that said, have used the 55 amp Duralast 7122 alternator sourced thru Autozone for 2 decades now with excellent result ... as just demonstrated. I think I might have replaced mine in 2012 when I rebuilt the engine just for kicks and grins but definitely not since. .. so it is at least 8 years old and replaced back then only to have a nice fresh new looking one.  These are an original style and design alternator rated at the max 55 amps for 63/64 Cadillacs, and a simple unbolt the old and bolt in the new alternator deal. Unless you have some megawatt sound system with a mutli-amp setup, or hydraulics or some other electronics that pulls tons of current 55 amp is more the sufficient.

I also keep a stock of these new ready to ship for $50 which is the same price AutoZone currently sells them for minus the $25 core charge they require. I can also ship 2 to 3 day Priority for $15 for a total of $65. 

If interested shoot me a PayPal to [e-mail] and will have one on the way tomorrow morning.  Be sure to include shipping address.

I would still recommend doing the 12 to 24 hr battery only test. Charge it up, unhook the battery cables and go back and check it tomorrow.

[Jason Edge]

"The stock alt is 50 v but they will be giving you an upgraded 60 v ( same external look as your stock one ) which Is not an issue at all". 
Not exactly correct:
- The stock alternator for non ac cars in 1963 and 1964 is 42 amps (not volts).  
- The stock alternator for 1963 AC cars is 52 amps.
- The stock alternator for 1964 AC cars is 55 amps.

Most auto parts stores can special order an original style alternator. Most will be 55 amps and will be about $50 to $70 + a $15 to $25 core charge and will need to be shipped to the store or customers home.  You can get higher amp alternators for a cost, or alternators with internal regulators. I have found the 55 amp AutoZone Duralast 7122 alternator a very depending original style replacement and one I have used and sold for over 20 years.

[Jason Edge]

Alternator may not be the only problem but is A problem if car has factory wiring and battery is disconnected and everything electrical turned off and car shuts off. If nothing else disconnecting the battery takes a bit of drain off the alternator since it is also charging the battery and voltage shoud actually increase a bit.  I would still test the battery and probably replace the voltage regulator and of course check all the wiring. 

[Jason Edge]

Mark, I will also take a bit of exception on the 'shadetree' comment. I've had several batteries in the last few years that showed OK using a 'load tester' by the 18 year old clerk behind the counter using his $200 load tester, with me knowing full well the battery would not take and keep a charge for any length of time. If I charge a disconnected battery and go back and it is 11 volts in a few days the battery is discharging regardless of what the clerk at the counter doing a 15 second or short period load test says.   I also indicated in my 1st reply "Also make sure all connections from alternator to battery and regulator are tight and alternator is well grounded via the one ground wire with loop connector."  Some times you just have to use common sense. 

[Kim K Kaiser]

I did check my alt an batt connections early on.  Made sure they were sng and bolted down

 Properly.    I can say those wires do look old,   but so do all the rest.  I hv new belts on ac, alt and pwer steering,   all new belts all around.  

[Jason Edge]

Mark, "An alternator is a very simple thing.   If you apply power to the field, it magnetized the armature, and if you spin it while it's magnetized, it makes power."
The reminder of electromagnetism is fine for those that do not understand it but I do not need the lecture.
"You can't say the alternator is bad, simply because you unplug the battery and it dies."
You can if everything else is correct including all wiring, voltage, regulator and the belt is on.  It is a process of elimination.  My stipulation was that everything else was in order. 

[Kim K Kaiser]

Well, in my decision making process at this point in the age of car, and reviewing old records  i cnt see where the alt was ever replaced, and prior owners kept recepts from oil changes.  And while there may well be some wire problems, not related to connections[just old] a replacement of the alt was due as well as the regulator.  If these parts dnt solve the issue, then at least i know what it shoukdnt be, asuming new parts are properly functioning.   I hv had the battery on over 24vhour chg and will ck it  later today.  Like i said earlier its 2.5 years old.  And rerecentky, we hv had minus 12 cold, so it may also be on last leg as well.  I appreciate Marks electrical input, albeit its over my head. Truthfully, the only thing i know about electricity is it hurts when you get hit with it and life is a pain without it.  I just dnt understand it.  I kno thatvjust throwing parts is not really bestvway to solve problem, but, for 125 i parts ,this time its worth it.  The lessons from all the input are appreciated and stuck in my aging memory bank for the future.  Again thanks

[Kim K Kaiser]

Gen light comes on at start, then goes off.  As it has always done since i had it