Battery wont start the car ,ill charge the battery its ok for a few hours then its dead ,alt charging good ,battery is new,every fuse in both pannels are hot with key off please help

Deville 92 old. lots to find bad that old. !
here it is, ID #2 below
you were told wrong, the reg is inside the ALT, actual.
the internet lied again.; 1/2 the time, asking 8year kid same.

the top parts sellers online,shows, no REG outside, so strike 2 on reg outside.

learn to keep that old (how old is it?) battery charged fully until car runs perfectly. or it can take 1/2 to jump start it or worse. dead batteries do not start engines and overload the poor donor cars electrics, doing so.(jumped)

once battery is new, or charged or load tested in a real shop
start the engine, see if GEN/CHARGE lamp goes out.? on dash.
if not alt is bad. wow no fuse then, scary then. lots of car fires.
or use voltmeter idling, at bat terms. 13,to 15vdc good below ALt is dead
140amp alt here.

https://www.rockauto.com/en/catalog/cadillac,1992,deville,4.9l+v8,1025738,electrical,alternator+/+generator,2412

That battery lamp is really named wrong, it is the Alternator (gen) lamp, and if it glows, most times the ALT is bad
or fuses blown. 3 fuses, #1 ,#2 fuse and # alt-s,,
this makes the battery go dead, parked or driving. dead ALT.
so , charge the battery first using a thing called a battery chargers.
if that sounds hard, tow the car to any ASE shop to fix it.
walmart does batteries new but never do the do alternators. new.
see? only real shops do it all. end to end.

The whole car runs off that Alternator, (gen) if bad the battery goes dead fast, even in 1 hours driving, and then car stalls or you
key off and the starter can not crank the engine now, that the battery is mostly discharged.
to start the car a jumper cable start up will work but we see removing the cables the engine stalls that is a dead alternator
the car the lamp glowing is called CHARGE lamp, and is wired directly to the ALTERATOR pin B4 AND WHEN GLOWS

• ALT IS BAD,
• 3 FUSES TO ALT ARE BAD.
• OR BELT DRIVING ALT IS LOOSE OR SLIPPING ETC.

pin b3 is ECU controls of ALT.

give your local mechanic a call sounds like you alt. has died

have the charge system checked by an auto electrician , especially the voltage regulator

Did you test the new alternator before putting it in. May be bad. Once you put it in turn the key and it self energizes unlike the older cars like vw. So if you forgot a wire or a plug to the alternator if it's good. Once the battery is connected it should be all set. So if that's not the problem you have to start looking for bad connections or melted wire and shorted a online fuse. Check your fuse box for any bad fuses.

Some vehicles are fitted with a smart charging system that is designed to prevent the alternator charging during acceleration to free a few horsepower to help.

My experience of these is very limited but there is an ECU that controls them and the battery, charging or ignition light using information from the engine management system.
The alternator generally has an extra plug with about four or five wires which when disconnected render the alternator a standard machine sensed type.

Japanese vehicles used separate voltage regulators longer than most types. You either need experience or a wiring diagram for good fault diagnosis but mostly it is unnecessary to check the charging current of an alternator which bears little significance unless being tested with a graduated load or adjustable carbon pile.

The current output of a healthy alternator is dependent on the terminal voltage of the battery which in turn is dependent on the electrical load placed upon it. Switching on the lights should lower the voltage and increase the alternator output. If the battery is particularly good the voltage won't fall very much and the current won't increase as much as expected...

Measuring the battery voltage with the engine running at about 2000/2500 rpm is sufficient for most purposes. With nothing switched on and a fully charged battery it should be around 14.5 volts and with everything switched on (lights, HRW, heater fan, etc.) a healthy alternator should continue to maintain a voltage above that of a healthy fully charged battery (13.2 volts).

If the voltage isn't maintained on load the charging system, probably the alternator, is faulty and should be independently tested.

91 , (is the charge lamp glowing key on, (shoe drops)?????
there are many ways to make it stop doing 13.3v to 15vdc running,
lots. ill list them all..
the 2 stated. in blue above. and.
1: bad dash lamp this lamp boot staps the field current or the alternator is born dead. so is it dead key on, , yes, BINGO.

2: bad alt ground, or starter top bolt , ground to battery bad or loose.
3: bad wires to the rear of alt. all 3.
4: bad battery cables. (or just corroded ends or conn. wrong)!!!
5: alt belt loose or missing.
6: engine hot RPM not 750 to 850 Rpm if 500 BINGO.
and more.
http://www.fixkick.com/Charging/charging.html

here is the drawing.
IS the sense wire is dead, not 12vdc.???

http://www.fixkick.com/Charging/charge89.jpg


the reg inside can shut the ALT down for.
over voltage
over current.
or if it THINKS(sic) that the batter internal resistances is too high. for ANY REASON what so ever. it will shut down
these protections prevents the ALt. from blowing expensive electronics (all of it) to kingdom come. $$$$$

its a feature.

Hi Paula, As both the battery and alternator have been replaced, there are only few remaining reasons why the alternator will not charge. Make sure of the socket connection being fitted correctly and that there is a good connection on each of the connectors inside the connector. Check and make sure the earth earth connection between the battery and the engine is correct and that both ends are tightened correctly. Inspect the 'Alt' fuse in the fuse holder and also the fusible link. Also make sure that the belt is tight. Regards John

Check for a blown fuse, if I remember right Oldsmobile had a charging fuse in those years.

First tell me why you don't think it's charging.
Because of the voltage reading you are getting at the battery terminals? The range you want is between 13.6v to 14.2v. The higher the voltage the lower the amps. and true the other way, the lower the voltage the higher the amps. If you get a reading of 13.6v or lower, the alt is nearing or at max output. An alt can only run at maximum for around fifteen minutes and it will start slinging solder from overheating. It's a good indication the battery is either totally dead or junk. Charging above 14.2 the alternater is running wide open and is only putting out high volts which will cause the battery to boil , in turn destroying it. This is a bad alternater. All alternaters have integrated voltage regulater with the exception of ver few of the earlier ones. You cannot test an alternater by removing a battery cable to see if the engine keeps running without taking great risk of damaging the alt, regulator. So tell me why you feel it isn't charging. Remember an alt is not made to charge dead batteries. Their sole function is to maintain the battery charge. Without a battery, the alt won't last 10 seconds.
Hope to hear from you and good luck.