How To Check For Draw With Southwire Multimeter

You walk out to your car/truck, turn the central, and yous hear the glorious click-click racket. Overnight, you lot've had a battery drain, but you didn't leave the lights on. Who knows where the bombardment cables are, and you oasis't recharged your jump-box since the last camping trip. Yep, we've all been at that place. Nosotros'll show yous the uncomplicated manner to observe a parasitic battery drain; in other words, we will discover what has caused your dead battery.

Southwire Multimeter - 14090T

Set to Amps DC – Pay Attending to Wire Leads

Tools Needed:

Multimeter – must have an Amp (DC) reading – at least 10 Amps (We used the Southwire 14090T)
8mm, 10mm, 7/16, or 1/2″ Wrench/Socket – to remove your battery last
Needle-nose pliers or Fuse-puller – for removing fuses from the fuse panel/s
Zip-ties or small clamps

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What is a Parasitic Bombardment Drain?

Information technology doesn't involve parasites in your battery, so that's a good matter. No demand for HazMat suits, yet! A parasitic bombardment drain is just something that consistently and continually drains your battery. This could exist a faulty relay, a headlight/dome-light switch, alternator, or whatever other electrical gremlins. Taking your auto to a mechanic with an "unknown" culprit can cost you big bucks as well. Most mechanics don't enjoy diagnosing electrical issues.

How To Diagnose the Battery Drain

Yous should be able to diagnose your battery bleed consequence within a few minutes. An extra helper may help with this project, simply it'southward non needed. Continue in mind, depending upon your vehicle, you probably have more one fuse console. Most vehicles accept at to the lowest degree ane fuse panel under the hood, and another inside the passenger area. Some foreign cars have multiple fuse panels inside, in different areas. You may want to check your owner's transmission or check ane of the forums.

Parasitic Battery Drain

Remove Negative Cablevision

Step 1: Remove Negative Battery Cable

Parasitic Battery Drain Neg Cable

Negative Cablevision Removed

Using the right wrench or socket, remove the negative bombardment cable from the battery mail service. In our case, nosotros were working on a 2000 Ford Explorer, and so the battery last used an 8mm bolt. You tin can perform this examination/diagnostic past using the positive or negative cable, only using the negative is much safer. Grounding a negative wire to footing is non a problem; notwithstanding, grounding the positive could destroy electronics, including your multimeter.

Step 2: Cheque the Draw Across the Negative Cable and Battery Postal service

Plough on your multimeter and select the Amps (A) and brand sure it's set for DC (Direct Current). You should see a symbol like a solid line, with dashes underneath. You Don't desire Ac (~), this is for your home'south electric. Y'all volition probably have the choice for Amps or mA (milliamps), then choose the Amps to first with, preferably 10A or 20A. Make sure your wire leads are in the right location, on the multimeter. There should be a diagram on the multimeter, showing you where to put the exam lead wires.

Southwire Multimeter Test Leads

Yous're going to be putting your multimeter in serial of the bombardment bleed or current draw. This ways the electric current draw volition be passing through the multimeter. In our case, we had a 4.4 Amp draw, then that power was flowing through the multimeter. Be certain your leads and dial are in their right locations.

Parasitic Drain Zip Tie Leads

Place one of the wire leads from the multimeter (it doesn't matter which one) on the negative battery mail and the other on the disconnected battery cablevision. You should see the multimeter display the number of Amps that are actively causing your battery drain. Use nil ties or minor clamps to continue the multimeter leads continued to the battery final and battery wire.

Tip: A normal operating vehicle volition have about fifty milliamps of Amp draw on the battery.

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Step iii: Remove and Supercede Fuses

First with your underhood fuse panel. Make sure that you tin run across your multimeter while you lot pull fuses. Use your needle-nose pliers or a fuse puller to remove and replace fuses, until you lot run across the Amps on the multimeter drop. Be careful that each fuse goes back into the correct location.

Parasitic Drain - Remove Fuses

Remove Fuses

If you get through all your underhood fuses, then motion into the inside fuse panels. This is where an actress person can aid, they can monitor the multimeter while you pull fuses. If you don't accept help, the leads on the multimeter should be long enough for you to place the multimeter face-down on the windshield.

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Step 4: Isolate and Fix the Event

One time you lot pull the fuse that is the culprit, then you can fix the issue. In our case, information technology was the Alternator/Voltage Regulator that was pulling more than iv Amps continually, which turned out to exist a faulty alternator. Once we removed this 30A fuse, the Amp draw dropped to 0.2 Amps, which is still more than typical. We besides constitute a secondary draw with the Interior lamps relay/switch. Removing both fuses dropped our Amp draw down to well-nigh nothing.

Nosotros replaced our alternator, and we'll replace the interior switch some other fourth dimension.

Fix Battery Drain - Issue Found

Step 5: Replace Negative Bombardment Cable

Now that you take the upshot/s fixed, you can remove the zip-ties/clamps from the multimeter leads and supervene upon your negative bombardment cable. Yous should be skilful to get, and your parasitic bombardment drain has at present been fixed.