parasitic loss from battery!

[69camarokid]

for the last 6 months or so ive had an issue with my battery dying after 2 to 3 days with no use. This happened about the time i had to rebuild my heads after the car overheated and cracked a head. Ive seemed to have this issue ever since that rebuild.

for the last 6 months ive just taken the battery posotive side off after driving. im tired of that and want to address the issue.

I tried this idea that was recommended to me.

Remove the negative side battery cable from the negative battery terminal.

2
Connect the black wire to the com input on the multimeter and the red wire to the 10A or 20A input on the multimeter. the meter needs to be able to read at least a 2 or 3 amps for this test to work. so connecting the red wire to the mA input on the multimeter wont work.
3
Attach an multimeter(set the dial on the multimeter to measure Amps as per multimeters instructions) between the negative cable and the negative battery post. Wait a few seconds to several minutes for the car to go into sleep mode - i.e. when you make the contact with the ammeter, the cars computer systems "wake up". After a bit of time they will go back to "sleep".
4
If the ammeter is reading over 25-50 milliamps, something is using too much battery power.
5
Go to the fuse panel(s) and remove fuses, one at a time. Pull the main fuses (higher amp ratings)last. Be sure to observe the ammeter after pulling each fuse.
6
Watch for the ammeter to drop to acceptable drain. The fuse that reduces the drain is the draw. Consult the owners' manual or service manual to find what circuits are on that fuse.
7
Check each device (circuit) on that fuse. Stop each lamp, heater, etc. to find the drain.
<LI class="steps_li final_li">8
Repeat steps 1&2 to test your repair. The ammeter will tell you exact numbers

I tried every fuse on my box and got zero drain. I had consistent 71 milliamps being drawn. Does nayone have any ideas on what could cause this or any ways to find and solve this problem.... thanks !!!!

[taz]

A shorted diode in alt can cause draw . Did you use wiring harness and fuse block with relays from donor car . Unplug relays also .Is something wired direct to battery voltage at ignition switch . An amp for stereo maybe radio radar detector ? If pulling fuses didnt work start unplugging things one at a time to isolate circuit .
Tim

[Type73LT]

I over heating the motor or in the repair you may have cut the insulation on a wire and that could be shorting on the metal. Are all your wires in the plastic lums to protect them? Anything you may have added ie; electric fuel pump, radio or amp etc must have an off switch. Amps have a remote off switch and a main power line. The remote could tie into the radio like the power ant or a switch by itself. A wire may be rubbing any where. It may work if you go a very dark area at nite. Turn off the car and move wires around. See if you see any kind of a spark. For a two to three day draw it may be pretty small so you need it dark. Just a quickie...your dome light does go off ...right?

[69camarokid]

I over heating the motor or in the repair you may have cut the insulation on a wire and that could be shorting on the metal. Are all your wires in the plastic lums to protect them? Anything you may have added ie; electric fuel pump, radio or amp etc must have an off switch. Amps have a remote off switch and a main power line. The remote could tie into the radio like the power ant or a switch by itself. A wire may be rubbing any where. It may work if you go a very dark area at nite. Turn off the car and move wires around. See if you see any kind of a spark. For a two to three day draw it may be pretty small so you need it dark. Just a quickie...your dome light does go off ...right?

all the wires in my repaired area are insulated. My amp and stereo stuff was all installed years before this issue arose. But ill start checking stuff and see what i can find.

[MonzaRacer]

OK which alternator are you using and is it computerized?

[Apogee]

How old is your battery? What brand? Have you had it charged and load tested recently?

I agree with the others that you seem to have a short somewhere, however a weak battery will make it that much more noticeable.

[69camarokid]

the alternator is a stock 95 trans am LT1 alternator replacement. Got a new one a a year adn a half ago i believe.

Id have to go check the battery, but its a very good Gel battery. Nice name brand. 200 bucks. 930 CCA. Its heavy duty and works extremely well

[silver69camaro]

Something doesn't seem right. A 75 mA draw shouldn't drain a battery in a couple days.

Somebody correct me if I'm wrong, but quickie math says a 50 A/hour battery should last about 650 days on a .075A draw. Perhaps the battery isn't getting fully charged, or unable to hold a charge?

[parsonsj]

Perhaps the battery isn't getting fully charged, or unable to hold a charge?That's my vote. I think you need a new battery. I just sent two "gel type name brand" batteries to battery heaven. My current battery is from Wal-Mart (it's true! -- Wal-Mart rebrands batteries from the three main battery manufacturers, and mine was actually made by Johnson Controls) and all problems are solved.

jp

[ErikLS2]

I'm with JP and Matt. 75 mA draw won't kill a battery that fast. The new cars I work on have that kind of draw or a little more and won't kill a 575 CCA battery in a week.

A company called Midtronics makes a killer battery tester that we use. Not sure if auto parts stores have them (over $1000) but most good quality repair shops will. Try leaving the battery disconnected and see if the same thing happens after 2-3 days, I bet it does.

[69camarokid]

ok, so last summer my car died from overheating because as it turned out my fans were hooked to a dead power wire. It wasnt til after i rebuilt the top end and hooked the fans to a good power wire that i had my battery dying issue.

Now when i tested the battery for milliamp draw last week i had forgotten that my fans had lost its ground wire and thus the fans wernt able to be used. While the fans were out i couldnt get enough draw to kill the battery as u guys posted earlier.

This leads me to believe that my fans must be what is drawing power from my battery and killing it. Ill test the milliamp draw from the battery now that the fans are reattached and see what numbers i get.

If it turns out to be that then ill need a lil help in figuring out how to stop the draw. thanks in advance

[Josue]

Sounds like the EXACT same issue we're having with our '68 Firebird. Something's draining the battery, and we can't figure it out. We're ALSO having overheating problems! Even 3 hrs at the dealership didn't yield any results, on either issue. In the mean time, we installed a battery quick-disconnect that we loosen after parking the car, and tighten when it's time to go. PITA, but at least it's a temporary fix.

Still driving us nuts that the solution can't be found yet. It's even more frustrating that all this stuff is greek to me, and we can't seem to find anyone anyone local to help us.

[69camarokid]

ok so two things.

1. the fan idea did not work... in fact i seemed to pull less draw with the fans plugged in.

2. turns out im retarded and dont know how to read a multimeter because i was drawing 71 milliamps....

i was drawing 710 milliamps!!!!

[absintheisfun]

You'll laugh at me, but this is kind of exciting for me. I am in school right now for Comprehensive Auto Tech and we just just covered parasitic draw this week. Here is the way we were taught to locate parasitic draw, and the "acceptable draw"

Disconnect the negative batt. cable and use your multimeter as part of the circuit (black to COM, red to 10A and dial to mA/A selection. Put one lead to the loose cable and one lead to the terminal DON'T BREAK THIS CONNECTION or it will have to cycle all over again.
It will display a high amount at first (1000mA or higher) but will stair step down as the ECU and other circuits shut down.

Acceptable draw: Take the reserve capacity of the battery and divide by 4.
ex: RC=100, so acceptable draw is 25mA.

Once the draw stops dropping(can be anywhere from 30 seconds to several minutes) start pulling fuses one at a time. If you find a significant drop after pulling a fuse, get the wiring schematic for that circuit and measure the voltage draw throughout this circuit and verify it against the schematics.

If you have no drop from the fuses, start hitting the things under the hood (alternator, electric fans, alarms) anything aftermarket that has been added.

Ultimately you will find a significant drop somewhere. If you never find one, I would leave the multimeter on the battery and randomly check it over a few days and see if it ever spikes...if it does, start the fuse pulling again and hopefully you have found your problem. If the ECM is going bad, sometimes it will turn on and off random circuits at random times. So there is a bit of luck involved...just don't ever pull the multimeter off!

One very important reminder-Do not ever change the voltage draw or it will all reset. In otherwords, do not open doors, turn on lights or anything that draws power.

I used my 93 Typhoon to test on, and my draw was 29.5mA. A very acceptable draw on a vehicle of that "vintage."

Good luck!

[MrQuick]

those tests can be very helpfull.

Some times good computers with cycle test circuits such as o2 sensor heaters and evap purge solinoids.

One tip for shorts and or parasitic draws...look for moisture damage and heat.
Vince

[maverickmk]

I like the idea of using the multimeter as a part of the circuit. I'm going to have to copy that down.