QuestionA 1958 chevy delray 6 cyl battery keeps draining out. ive replace alternator and voltage regulater along with new battery.I did the good and bad alternator test by removing the battery cable. the motor stays on.But two days latter the new battery is dead. please help
AnswerYou've changed a lot of things and spent a lot of money, so we know the battery is good, and the generator and voltage regulator are working well. That's good, but the most important thing is to find out what is DRAINING the battery.
The way to do this is to start the engine (jump it if you have to), drive the car or at least run it at fast idle for a half hour or so to make sure the battery is pretty well charged, then turn off the key, then disconnect the postive battery cable from the battery as soon as you turn off the engine.
Wait until after dark, then tap the loose end of the battery cable against the positive post in order to see if there is a spark when it makes and breaks contact - just tap it to see if you can see a spark. If you do, skip the next three paragraphs (discussion about getting a volt-ohm-ammeter) and jump down to the discussion about finding a current drain. The spark tells us there is current flowing out of the battery when the cable is connected, in other words.
If you don't see a spark, you will need to beg, borrow or steal a Volt-Ohm-Ammeter. Set it to the least sensitive DC AMPS scale - which will probably be either 10 AMPs or 30 AMPS - (but it doesn't really matter, we're just being cautous and avoiding overpowering the meter when you first connect it).
Next, connect the meter's "+" test lead (probably red) to the battery's positive post, and it's "-" test lead (probably black) to the disconnected end of the positive battery cable.
If you don't get much of a needle movement on the meter, select a more sensitive scale scale and keep trying lower ranges until you get a reading. If the battery is going dead in two days, you have a current drain of at least 1 ampere, probably, which you can see even with a fairly inexpensive meter. To test your setup, you can open the car door so the dome light comes on to see how the meter reacts to that. It should show a drain of about 1/4 amp for a single dome light bulb (also called 250 milliamperes).
Whether by noting the presence of a spark above, or by using a meter, if you do find a current drain, (and I think you will), you've found your problem - something in the car that is supposed to be turned off when the car is parked is staying on. In other words, something that doesn't go on and off with the key is drawing current when it shouldn't be (the glovebox light, the trunk light, the underhood light, the cigarette lighters, the horn relay, the parking lights, the clock - any electrical equipment at all that stays on even when the key is off.
I have no way to guess what it is, and of course someone in the last 50 years might have changed how the various items are wired so that things that are supposed to go off with the key might be mis-wired so they are staying on even when the key is off. This could be things like a power antenna, power windows, power seat, radio - it could be anything electrical on your car. Electric wiper motors are famous for this, if the parking circuit isn't wired right.
The way to find ithe offending item is to disconnect items, one by one, until the current drain goes away - or at least drops below one tenth of an ampere - the lower the better. In a perfect world, you should be able to see zero current drain (less than 1/1000 of an ampere, also called one milliampere), but some cars always have a tiny bit of current drain due to spurious conduction from corroded terminals etc. If you get it down to less than 1/100 of an ampere (also called 10 milliamperes), you should be able to leave the car for a week with the battery hooked up without having trouble.
A fully charged battery contains around 60 ampere-hours - so theoretically it would still be able to start the car after 2 days with a drain of 1 amperes - but that would be equivalent to a pretty bright light staying on (brighter than the dome light for instance).
To recap, then, I think something is draining the battery, and you are just going have to do the detective work to track down which item it is. One way to do this is to start pulling fuses - one by one, until finally the current drain doesn't occur any more - the last fuse you pulled is for the circuit that is draining the battery.
I hope this is clear enough, and that you are comfortable with doing these tests. If not, I think you need to take the car to an automotive electrical shop and just let the pros find the problem.
Good luck!
Dick
