Battery draining issue.

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Devon101

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Good evening.

I need some help with a issue thats been bothering me for the past week. I have a 1995 Toyota Corolla and the battery drains flat if the car is off overnight. The battery and alternator has been checked and both are fine. The alternator is new and replaced recently. If i take the negative off, nothing drains. I just reconnect and start as normal. If i leave it on, the battery is flat to the point that not a jump start or kick start works.

There is a sound system but even if i fully disconnect it, the battery still drains. So that has been ruled out.

What could be causing the battery to drain? Earth wires have been checked and all are working.
 
With a car this old, one of the wires plastic is of and it is touching to the body. Or plastic got hard and brake off and touching the body. Does the car have a radio. I will check the harness and wiring, after that a megger set to low volt.
 
Just remember, set the DMM (digital multimeter) to 10 amps first, connect the lead in the 10amp DC socket, remove only ONE battery cable, and put the DMM in series with that cable and battery. Check the readout in amps to measure parasitic draw.

If you accidently connect an unfused cheap DMM which is plugged into the 10amp socket and touch both leads to the battery in parallel (as if you checking voltage), you have just shorted the battery. 7000+ amps. Kaboom. Expect melted wires at the least.

I'm talking from experience. Don't F around with lead acids if you don't know what you are doing. Tripple check the connections you are testing, settings on the DMM and socket on the DMM before touching the leads together to do your test.
 
upup said:
With a car this old, one of the wires plastic is of and it is touching to the body. Or plastic got hard and brake off and touching the body. Does the car have a radio. I will check the harness and wiring, after that a megger set to low volt.
Click to expand...

Multiple old tracking devices hidden god knows where can be a culprit too.
 
Good morning.

I got a multimeter and checked for parasitic draw on Saturday. There was some power being pulled bit it stayed the same while checking the fuses. My nephew checked his system again and found a burnt wire. He then removed the entire thing and we left the car for a few hours. The car started fine as it should. On Sunday morning it was dead again. It started after a slight push as there was very power left. The car was parked and we decided to check again the evening but it was deader this time. We had to switch the battery to start the car and then put in the dead battery for it to charge. The car left overnight with the negative removed but still needed a push to start.

Either we tested for parasitic draw incorrectly or there is something else wrong. A @upup mentioned, there could be an exposed wire but where do you start looking?
 
TheChamp said:
Check the boot light, sometimes it doesn't go off because of a faulty switch, but checking the parasitic current draw will reveal the offending circuit.
Click to expand...
There is only 1 interior light in the car. All lights are off but power is still being drawn.
 
Also, the videos on Youtube shows normal draw is 0.02 to 0.05. It was reading around 2.70 with the car off. The lowest it went was around 2.50.
 
process of elimination, going through everything trying to find what is causing the battery to drain, could be anything, old immobilizer, tracking device,
luggage light, or trailer wiring,

hunting these can be quite tiresome.
 
Jet-Fighter7700 said:
process of elimination, going through everything trying to find what is causing the battery to drain, could be anything, old immobilizer, tracking device,
luggage light, or trailer wiring,

hunting these can be quite tiresome.
Click to expand...
Car only has an immobilizer. We haven't used it since this issue started. Ill check that as I am out of ideas.
 
Pull off a fuse one by one until the high draw goes away, then you can roughly get an idea where the issue is.

When you pull out a fuse, put it back then move on to the next one so you dont mix the fuses up.
 
Last edited:
Devon101 said:
Car only has an immobilizer. We haven't used it since this issue started. Ill check that as I am out of ideas.
Click to expand...
what immobiliser is it .units from the mid 90s had high standby drain ,also are your amps turning off ,disconnect the blue wire from each amp .
 
Rickster said:
Pull off a fuse one by one until the high draw goes away, then you can roughly get an idea where the issue is.

When you pull out a fuse, put it back then move on to the next one so you dont mix the fuses up.
Click to expand...
This, you can narrow it down to the most likely culprit circuits so that you don't have to pull every fuse. Since it's a 95 Corolla that should be very easy, radio, cigarette lighter, lights, both internal and outside, alarm and immobilizer.

If you don't come right there you can expand your troubleshooting to other circuits.
 
Devon101 said:
Good evening.

I need some help with a issue thats been bothering me for the past week. I have a 1995 Toyota Corolla and the battery drains flat if the car is off overnight. The battery and alternator has been checked and both are fine. The alternator is new and replaced recently. If i take the negative off, nothing drains. I just reconnect and start as normal. If i leave it on, the battery is flat to the point that not a jump start or kick start works.

There is a sound system but even if i fully disconnect it, the battery still drains. So that has been ruled out.

What could be causing the battery to drain? Earth wires have been checked and all are working.
Click to expand...
Immobiliser perhaps.
Set multimeter to amps, disconnect one of the leads and connect the meter in series between that lead and your battery. Test briefly while removing one fuse at a time until you find the circuit.
 
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