Help Battery running down GOING NUTS

My 65 in the last week has developed a Battery problem...After about three days sitting in the garage it is completely dead..I jump start it and run it a while and it will start all day till it sits again for a few days...I have climbed in the trunk and had the wife close the decklid,yes I know thats a little risky on my part but she released me.The light goes out in the trunk and stays out,the glovebox light is going out and so are all exterior and all interior courtesy lights and the stereo...Any ideas? I am thinking maybe a bad battery but why would it be fine till I let it sit a few days then its dead...Thanks

 

Using the test lite and pulling fuzes is a great procedure. Just as a quick check of something, next time the battery is charged up and the car is shut off, wait a few hours til everything is cooled down and see if the alternator is staying warm. Sometimes one of the diodes will go bad and let current from the battery backfeed thru the alternator. Runs the battery down eventually, but usually there's enough current flow to make the alternator a little warm.

 

Could be a bad battery too. If one cell is bad ( shorted ) it will slowly draw from the good ones and eventually kill your battery. Try disconnecting the battery cables for a couple of days and if it's dead when you reconnect it's the battery. Good Luck

 

Thanks to all for the advice...I will give the test light procedures a try tommorow.......Hope I get it figured out as I am getting frustrated.I can rebuild engines and trannys but this damn electrical crap throws me fits.......

 

if u have a clock in your dash that is connected, the test light will be on.

 

Charge the battery, get it running and test the voltage.

I had the same problem, and my Voltage regulator had gone bad. Basically it stayed ON all the time, which overcharged/killed my battery and drained it overnight.

My condition showed I think 16V when running. Basically it full fields the alternator at all times.

good luck!
Ken G.

 

kinda off subject but, i have a similar problem, ill crank my car and start driving alitte ways down he road, then the lights and stereo will cut off for like 3 secs, and come back on but on, but only does it when u hit a bump, i checked all wireing looks ok, next ill stop and park the car, come back and try to crank the car it says nothing like the battery dead, so i pop the hood and check the connections on the battery, then kinda move the battery where u can hear the liquid move, go back and turn the key and the car cranks right up, im kinda thinking its a dead cell in the battery, what do you guys think.

 

I had a similiar problem with my 67 Skylark, but it wasn't charging thus the battery run down. I finally decided to do a major overhaul! I got a lifetime alternator, new external voltage regulator and a new battery. I remounted the ex reg in a different spot on the firewall with some smaller sheet metal screws to get a good ground. Also replaced a couple fuses that had a slightly bent filament. Finally, I checked all the wiring in the engine bay and found some bare wires near the starter, wrapped some electrical tape around those and reconnected. A wiring diagram is a must. I also put on new pos and neg battery leads. It was alot of work, but the problem is solved! It's been charging fine ever since! No battery run down either!!!

 

Thanks evrybody,have been away a few days and just got to doing some of the stuff you advised me...When I pull the negative cable and put my meter between it and the negative post on the battery it definitley draws volts...I pulled all fuse one by one and still the same thing...I think Todd may have the answer in the Voltage regulator as when I unplug it the meter drops to about 1 to 2 volts instead of 12 when the regulator is hooked up.Still draws a slight current but not nearly as strong as when its plugged in....I will see what kind of voltage it puts out with the regulator hooked up and the car running.........Thanks so far and I will get back on tonight and see if I have figured anything else out.......

 

Bad ground. Clean off both ends of the negative cable also the motor ground both ends.
Lon

 

Lon I will clean the ends but I pulled the alternator off and had it tested and it tested bad,thats what they said anyway,so I replaced that and took the 6 month old battery back to Wal Mart and it tested bad also so now I have a new battery,alternator and also a new regulator...Will see if it runs down now...If it does it may be for sale cheap,LOL Thanks

 

Well I need more help....The wife drove it to work the other day and after sitting there for 8 hours it was dead.........This is what I have tried in addition to the new stuff now...I pulled both plugs from the firewall and it amazingly it stills draws power at the the negative cable and the negative cable sparks when I try to put it back on...In addition to this when I have the two main plugs on the firewall to the fuse box pulled the interior lights and radio still run with them unplugged...I have pulled every fuse to see if the thing stops drawing power at the negative side and it still does......If anyone has a idea that i have not tried I sure would appreciate it greatly.........AAAARGH

 

here is a regulator check from a corvette forum when a member had a similar problem. i hope this helps. i know nothing about elec stuff. jim

If your regulator clicks when you install the battery terminals you have a problem. Weather you put a mechanical or electronic regulator on it will not solve it.
Either you have a bad diode in the alternator which is leaking back through the white wire to the regulator or the wires are incorrectly placed on the regualtor.
Please read this article I wrote. It should help you with your diagnosis.

Here is a basic explanation of how an alternator/regulator works:
When you start the engine a voltage is sent to the number 4 terminal of the regulator, then it goes through the regulator, out the blue wire to the F terminal of the alternator.
This energizes the field of the rotor and creates a spinning magnetic field inside the stator windings of the alternator. This starts the charging cycle. Now a small amount of voltage is sent back out the R terminal of the alternator (white wire) to the number 2 terminal of the regulator. This closes a set of points and allows the battery voltage from the red/orange wire to power the field circuit. If you had an idiot light it would now turn off. The amount of field current depends on the electrical load that is placed on the system. Now that the stator is producing current it will maintain the battery and take care of all the loads that are put on the electrical system.
Remember the battery is there to start the car and add current to the system only when the alternator is not producing enough to cover the electrical loads.
So if you have 37 amp alternator and you have 40 amps of electrical loads, then 3 amps will be supplied from the battery. This means the alternator has no current left to charge the battery and the voltage reading across the battery will be below 12.66v.
A properly working system should maintain a battery voltage of approximately 13.8-14.8 volts depending on temperature.
Always check charging volts with a fully charged battery and engine above 1000 RPM.
If the battery is very low when tested, then the charging voltage will be low. As the battery begins to charge then the charging voltage will rise.
A fully charged battery, after any surface charge is removed, will read 12.66v.

Alternator/ regulator testing:
First, check for battery voltage at the stud where the large red or orange wire connects to the alternator. You should have battery volts. If not, repair the wire or circuit.
Then disconnect the plugs from the regulator and alternator.
Check the continuity of the blue (field) and the white (relay) wires between the plugs.
Repair any wire if they do not have continuity.
Reinstall the alternator plug and leave the regulator plug disconnected.
With a voltmeter, check voltage at the number 3 terminal on the regulator plug, it should read battery voltage. There should not be any voltage at the other three terminals at this time.
If you have voltage at the number 2 terminal, R on the alternator, you have a leaky diode in the alternator, replace the alternator. This will cause a battery drain and the regulator with be hot to the touch with the key off.
Now turn the key on, you should have voltage at the number 4 terminal, this wire comes from the fuse panel. If you had an idiot light, this would be from the bulb.
This is what is called the exciter circuit, without voltage to this terminal the charging system will not begin to charge.
If no faults were found so far, leave the regulator plug disconnected, make sure all wires are clear of the fan and start the engine.
With a voltmeter connected to the battery and the RPM at approximately 1000-1200, jump from the F terminal of the regulator plug to the 3 (orange or red wire) terminal.
You should see an increase in voltage at the battery and hear the alternator working. If you hear a growling noise from the alternator you have either a bad diode or a bad stator winding.
Dont leave the jumper connected too long because you dont want the voltage to go over 15 volts for an extended period of time.
If you dont see the voltage go above battery voltage after a few seconds then you have a bad alternator.
If the voltage rose quickly and then decreased this means you have a slipping fan belt.
Now connect a voltmeter to the number 2 terminal (white wire) of the regulator connector and again momentarily jump from F to 3. You should see about 8-10 volts.
If not, you have a bad diode in the alternator.
If all is OK up to this point reconnect the regulator connector.
If it is still not charging, run a separate ground wire from a good ground to the base of the regulator. Now if no there is still not charging, replace the regulator.
If you have an overcharging condition, it is either a bad ground at the regulator base or a bad regulator.
This is the basic testing procedure that I have been using for many years. There are other possible problems that can cause a no charge condition but they are rare and harder to diagnose.

 

I had the same prob on my Riv. turns out that the LR power window motor was drawing the power, like it was trying to go up and down at the same time. I found it by listening. It was making a very faint buzzing noise. I had been messing around with the wiring for a few days trying to get all the interior lights working and caused two terminals to short out. So think of anything that you may have messed with before it started. Good luck o No:

 

experiencing same thing with My '76 Electra. has been parked in my garage since late June. went to start it today, battery was dead. am charging it now.

my starting/charging system is in good shape. no current draw problems. (it sat for over 8 hours at the car show, fired right up when I left for home.)

 

i had a similar problem with a 1981 cutlass. it was the power antenna recycling itself.

 

I had to unwrap almost all of the wiring tape in the engine bay and inspect the wires. Found some bare wires that had no tape/insulaton around them. They were probably grounding out somewhere. Did you remount your ex reg in a fresh spot on the firewall? It absolutely needs a good ground while the engine is running or it will be trashed! Check your engine to body ground, body to frame ground, and battery ground. I had to go through nearly everything in my engine bay, but it's still working fine!