random battery drain

[KPeeZy]

For the past month my car's battery has randomly drained three to four times. Not from leaving my lights on, or anything else that I know of, but for reasons unknown the battery dies. The battery is 7 months old and the water is full in it. What could cause a battery to drain randomly. It's a crap shoot every time I go out to my car to find my alarm chirp or not. Please help

[evildky]

a bad voltage regulator can cause a battery to drain, it's built into the alternator and you ahve to replace teh whole alternator

but before we jump to conclusions, aftermarket stereo? aftermarket alarm? if so pull the fuses ont hese items at night asn see of the drain still occours, if not they are your source fo drain

[KPeeZy]

I do have an after market alarm and stereo including a small amp but these Ive had for 2 years without changing a thing with them.. The dead battery has been acting up for the past month only. Thank you for your feedback.. other mentioned it might be the alternator.. Ill have it checked out tomorrow.

[KPeeZy]

So I had the alternator replaced last week after the mechanic said that it was not charging the battery. Since then the same thing happen again... twice. Could it be anything else.. I noticed that there were three separate grounds coming from the negative terminal. Does this matter? Would that cause my car to randomly drain my battery??

[KPeeZy]

Do the cyliniods play a part in this??

[es.biggs]

It's probably your alarm. Your mechanic is a douchebag for changing your alternator. They are VERY easy to test, and that will tell you if it needs a new one or not - fool proof.

9 out of 10 times where there is a battery problem, its an aftermarket alarm. Have you tried unplugging your alarm as suggested above?

Cyliniods is really spelled "solenoids" and they are just really big relays, they are in tons of different circuits throughout the car.

[evildky]

so you replaced the alternator but did nto disconnect the aftermarket equipment ecause it's "2 years old" how old was the alternator you replaced? seriously, disconnect any aftermarket equipment and see fi the problem persists, it's quite possible that this is the problem and it's easy and free to test

[BigTDogg (MA)]

Could also be the passive belt circuit, as shown here:

http://twinturbo.net/nissan/300zx/forum ... drain.html

[KPeeZy]

Thank you for your responses... I took out the fuse for my amp and the fuses for my alarm. If the problem persists I will ask the mechanic about the passive belt circuit. He also told me that he could hook up an ohm meter to the battery terminals and start eliminating fuses that could be draining the battery testing for battery drain. How do you test for the passive belt circuit? Is it a fuse, if so where is it? do you have to take apart the door?

[KPeeZy]

Could it be a ground issue?.. I noticed there where 3 wires from the negative terminal that led to difference bolts to the body of the car.

[BigTDogg (MA)]

Could it be a ground issue?.. I noticed there where 3 wires from the negative terminal that led to difference bolts to the body of the car.

Nope, that's a ground net, and it's good

[es.biggs]

This type of battery drain is usually called a parasitic draw: something that stays on, drawing current from your battery even when the car is off. It can be something that kills your battery fast (having a high power amplifier staying on) or something small, that takes a lot of time to drain the battery enough to cause problems (ash tray light or glove box light) Here's how I check for parasitic draw:

Make sure you have a multimeter capable of measuring amperage. I think some cheap ones might not be able to do this. Disconnect your negative battery cable, and with your multimeter, place one lead on the disconnected cable and one on the terminal. This effectively puts your multimeter in the middle of the circuit - whatever current runs through your battery will run through the multimeter as well. With the car off and all loads off, check how much amperage is showing up on your multimeter. It should be under .050 amps, also commonly called 50 milliamps.

If you are having too much amperage, over .050 amps, start unplugging fuses one by one. What this does is cut the power to the circuits you unplug...I would start with the aftermarket alarm for sure. If your alarm is in fact drawing the current that is killing your battery, you will see the amperage go down whenever you remove the fuse. If the amperage is still too high or if the alarm fuse doesn't change anything, put that fuse back in. Then pull the fuse for the aftermarket stereo amplifier if you have one. If you have an aftermarket stereo, cut the power to that (should be a fuse or a remote wire that runs to the fuse box).

Basically start with your aftermarket stuff, then keep removing fuses until you pull the one you need out and the amperage goes down to an acceptable level. All this does is locate the problem. You will then have to look at the circuit and find the actual problem. Could be a short, could be faulty equipment, could be improper wiring. This is where expertise really comes into play...electrical troubleshooting is easy when you understand it but it can be intimidating at first. If you need help you can always come back here, or even get some help from a friend or a mechanic if you want to spend money.

I would definitely look at your alarm first, and other aftermarket equipment that is installed on your car. I bet the problem is one of those.

Of course before this test can be performed, your battery should be fully charged or close to it. If you can't get a good battery in there or if you can't charge this one, go ahead and try this test anyways to see what you come up with.

Sorry for the novel lol. Hey I just did a Google search and found something that goes over this same type of test in greater detail and some pics I think...take a look if you need mroe info!
http://www.bbbind.com/Bulletins_Attachm ... 20draw.pdf

[evildky]

not ohms, amps and yes thats a valid test

[KPeeZy]

I think I've located the problem... I went out to my car and here something like the exhaust cooling down under the car, but it was electric. I popped the hood and heard it coming from a hose that went to the engine. I could feel fluid, possibly gas, passing through it. The hose runs next to the fuel filter and it may go to an injector. It sounds like gas may be moving back and forth between the pump and injector. Keep in mind my car is off at this point. The hose looks like it comes from the same area as the one connected to the fuel filter. Bad fuel pump maybe?

[evildky]

a bad fuel pump does not pump

fyi

your have 1 pressurized fuel line going throught he fuel filter then into the fuel crosover assembly, which connects to the fuel damper which feeds the fuel rail

the fuel rail connects to all the injectors and then outlets through the fuel pressure regulaotr whcih si connected to the fuel crossover assembly, which then leads to the other fuel line which you described

if there is pressure coming through the return fuel line after the car shuts off you have a bad fpr letting the pressure bleed off which draws no power

did you perform the amp draw test outlined above?

[KPeeZy]

I spoke to another mechanic and he said its most likely the EGI fuse under the hood.. He thinks the fuel pump relay is sticking... Evildky, I havent done any tests yet because they want to charge at least one hour worth of work, then more to actually fix the problem. I ordered the EGI fuse and will replace it Saturday.

[KPeeZy]

battery was only running on 5 cells, I got a new battery.

[NORCAL300ZX916]

LOL you could have tested that yourself for free with a ten dollar volt meter! time for new mechanics who arent retarded. that should be the first test when a car doesnt start!

[KPeeZy]

its more than just my battery and alternator... What the hell is that hissing sound with the pressurized fuel line.