how to use a light tester to find battery draining problem???
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Teching In
Joined: Feb 2005
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how to use a light tester to find battery draining problem??? i have no idea what i need to do with the light tester to find out what is draining my battery? bought a new altenator and optima red top battery and it still drains down in about a day or two.....
Teching In
Joined: Sep 2005
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A test light? I'm trying to hunt down a drain myself, its a bitch. I was told that the first thing i should do is unhook the negative battery terminal, and touch one wire to the terminal, and the other to the post, both negative. That's about the extent of my wiring knowledge, so ill be watching this thread too.
TECH Enthusiast
Joined: Jul 2003
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From: Evansville, IN
First check for the obvious, make sure no interior lights are staying on. The glove box is a good one and so is the console light. There are small bulbs, but will drain a battery. A test light really isn't going to help much. A Voltmeter or Ampmeter is what you want to use. You can start by checking the battery voltage. Start pulling fuses and see if the battery voltage increases. If it does, this will indicate that their is a amperage draw on that circuit. Find out what the circuit is and locate the draw. You can also try and check the actual amperage draw, but this can be a pain with DC. You have to break the circuit and insert the meter into the flow of current.
If you’re using a test light, put it in series with the battery on the negative side. Make sure all accessories are off. If the test lamp is lit, there’s something draining the battery. Start pulling fuses one at a time, until the light goes out (once you pull the fuse, leave it out until you finish them all (you take a chance on waking a system up when you put it back in)).
Another way is to use an ammeter, hook it up the same way as the test light. There should be less than 500mA of draw, if there’s more you have a drain. Follow the same procedure as the test lamp, and check to see which fuse drops the amps the most. Most likely it’s in that circuit, and you’ll have to trace it from there.
Another way is to use an ammeter, hook it up the same way as the test light. There should be less than 500mA of draw, if there’s more you have a drain. Follow the same procedure as the test lamp, and check to see which fuse drops the amps the most. Most likely it’s in that circuit, and you’ll have to trace it from there.
Powering a system up. Putting a fuse back in can cause a system to power back on, interfering with the test. You also don’t want to open your door in the middle of the test, your interior lights will come on, and other things may power on causing an excesses amount of current draw which could blow the fuse in the ammeter.
