How To Perform A Parasitic Draw Test

Say you exit your vehicle sit for long periods of fourth dimension and the battery goes expressionless. You've either checked or replaced both the bombardment and alternator, and you know they're skilful. Then what's going on? You might accept a parasitic depict.

A parasitic draw is an excessive electrical load on the system that happens after the vehicle is turned off. In that location will be some activity and loads when you turn your vehicle off, your clock circuit for i. In many modern vehicles, when you lot shut down and remove the primal, a series of events happens that can describe electric current for several minutes after y'all turn the engine off. This is normal. To see if this is excessive and test for a parasitic draw, yous'll demand a DVOM (Digital Volt Ohm Meter) capable of testing amps.

Often, when doing this exam, you need to move your test leads on the DVOM to a different location when testing for amps, so exist certain to check for this. It's also important to annotation that you demand to make sure everything is off when doing your testing. Don't leave the trunk or any doors open, and make sure the cardinal is removed from the ignition. This way you're sure that there won't exist any electric loads that you lot induced when doing this exam that would give you fake readings.

To perform the test: Remove the negative bombardment cablevision. Some people remove the positive cable to do this examination, and that's fine, but I recommend the negative cable when doing parasitic draw testing. Put your meter on the highest DC amp scale. This might require that yous move your exam lead to a special location on your DVOM. Identify the leads in series between the negative cable and the negative battery mail and accept your measurement. If you see a negative number, switch the leads.

To be honest, information technology doesn't matter, because the readings will be the aforementioned. You don't want to see a reading in a higher place 50 milliamps. I know I told you to starting time with the highest scale, which might be close to 10 amps. If you lot don't encounter a reading when yous're on the highest scale, nifty. Yous want to do it this style because some amp draws tin exist pretty high, which could impairment your meter if you're on a lower scale. If you don't have a reading on the high scale, switch to the lower calibration. Don't forget to switch the leads if y'all need to. Once once again, you're looking for less than 50 milliamps. If you see a reading above 50 milliamps, your draw is excessive and it can drain the battery. The higher the reading, the faster the drain.

A couple of things to notation: Some modernistic vehicles, peculiarly luxury vehicles, accept systems that remain on afterwards the key has been removed and the doors have been airtight. These systems might remain on for upwards to thirty minutes after shutdown. Proceed this in listen when doing your testing. You might have to look with your meter withal hooked upwards for 30 minutes or more to get an authentic reading. Once you unhook the meter, things offset all over again.

So you've washed the test, yous've waited an appropriate amount of time, and you're still seeing to a higher place 50 milliamps. The next stride is to start removing fuses one by i while observing the amp readings. If you lot come across a sudden drop when removing a particular fuse, this is likely your culprit.

The next step after you find the offending fuse is to find a wiring diagram showing what's on that excursion. After that, it's a procedure of further emptying. Unplug each component in that fuse's circuit till the draw goes away. For instance, if the fuse controls the radio and power antenna, plug the fuse back in and unplug the antenna. If the depict goes away, you've narrowed information technology down to the ability antenna. If it doesn't go abroad, unplug the radio and recheck your reading. Yous're probably getting the picture at present. Here'southward a video about parasitic draw testing you might find helpful.

Video Title: Parasitic Draw Testing – Solving Automotive Electrical Problems – EricTheCarGuy Video Clarification: In this Article we talk about Parasitic Draw Testing that you can do with Your vehicle. Thumbnail: http://www.ericthecarguy.com/images/faq_buttons/Large_FAQ_Images/Electrical-icon-1200.jpg