How to find a short in a modern car fast and easy (The correct way)

hey guys how's it going today I'm gonna show you how to find an electrical shorting fast and easy now how do you know that you're an electrical short indica well let's say your car wouldn't start off for a few days or even after sitting overnight then the chances that you have a drain on you buried your potential short so I'm gonna show you a simple test that he can easily do by yourself at home to identify with Shorty's so I can easily fix the problem this video is geared to beginners we have never done an electrical work in their car so before we begin let me show you how this just to work in cast there are lots of electrical components and the wiring the supply current to make them work all these components get their current from the battery so when you turn them on for example let's say you turn the headlights on then the current from the battery find path to goes through the headlights so the headlights turns on car batteries country is very large currents so to stop the switch from going bad a relay is used in the circuit to stop the headlight and the wiring from going bad mainly due to a passage or a short a few C cells are used in the circuit so if you have a battery drain then the current has to go through the fuse because he can has many other electrical components and all these components need to be protected a separate phase and relay is used in each circuit the place where we can find these relays and phases is called the fuse box and all cars have at least one facebooks so if there's a short enemy in your cast electrical system then the current has to go through the fuse box all she had ready is to check all the fuses insert the fuse box one fish at a time to see which circuit raised the current now the location for the fuse box could be any way in the cut depending on the type car you working on it could be under the hood under the dashboard or you said the bird the exact location for accounts fees books is mentioned in your highness venue in the case of this car we have the face box right next to the Barry these small cubes right here that is your relays these tiny strips Danny these are your fuses alright now you are ready for the test first you make sure you have a fully charged Barry so you wanna get a multimeter you don't need an experienced you want for this even a cheap multimeter voltar then connect the black lid into the common Jack and the red lead into the voltage check then you wanna select 20 DC volts and connect the red lead to the positive terminal and the black lead to the negative terminal even a co-write in-between to 0.4 volts and 2 point 6 volts or about we have two 0.8 volts here so we are good if your Barry's lawn charge then you wanna connect the berry to a battery charger or you gonna start the car and leave the engine running for at least 30 minutes so the alternator will charge the berry once it Berry is fully charged they're gonna make sure you can everything off in the car now we have disconnect the negative battery terminals and keep it aside then you wanna get your multimeter again and turn the dial into 10 amps and you never have the red lead into this jack where it says state names the reason why we go for the highest amps is that we don't know how big is a current draw on the battery so if you select milliamps and the actual drain happens to be a larger current then we can have damage this multimeter by selecting the logical and first we are not risking the multimeter then even have breached the gap between the very first and the terminal so you're gonna connect the right lead into the very first and the black lead in its terminal now you gonna check the multimeter rating in most modern cars the Cask MPD is still taking some current from the battery even when the car is not running so if you are getting a rating up to 35 to 50 milliamps that is normal but we have 1.3 m/s that is one thousand three hundred milliamps and that is a significant drain so now we had to go to the fuse box but I only have two hands emily is a clamp and one alligator clip to keep the test leads connected to the very alright now gonna start pulling one fuse at a time what we're doing is really connecting one circuit at a time and what we're going to be looking is a drop in the multimeter reading as you pull off the fuses and there is now this is the circuit that drains the current so the shot is in this circuit then you wanna see what face it is it is the second row one two three it it from the top then you wanna go to the Facebook scour here's the second row one two three to it from the top and that is the fuse for the radio so let's go to the radio now we have to disconnect the radio then if the reading drops down to normal then the radio is faulty if the reading did not drop to normal then the shortest in the wiring harness between the radio and the fuse box so you gonna chase the wires that goes through the radio and the car parts or under the dashboard and that can be a real pain to find if that is the case with your car then you better get a circuit tester kit like this this kit comes with the transmitter and a receiver even a plug the transmitter to the face with a short circuit then the transmitter will start sending electric pulses along the wires the receiver can sense that signal so the receiver didn't start to beep all he had is to follow the rough position of the wire with the receiver if the ratio is stop vaping as you go on that is because the receiver cannot detect the signal and that is for the shortest but in the case of this car I don't think that we have any shot in the whirring or in the radio however I have one space sub before installing the bolt so I have a feeling that it could be the sub so let's get it the boot and here it is it doesn't look that bad at a glance but aha there is look what we get here we found the short the speaker has a shorted out parallely these whiskers are hot and it has even melted into the plastic so we're gonna have to disconnect sir now whoever installed this sub with a rubbish job using this really thin wires some using some proper speaker wires to rewire this so that is how you find a short in a car fast and easy here's one thing you need to know when you're doing this make sure you don't open any doors or do anything that draws a current from the battery because now we had a current from the Bary going through the multimeter and any excessive current flow through the multimeter will burn your multimeter let's say you have another fuse box under the dashboard then you have to leave the doors open but be sure to turn all the interior lights off before you begin this test we did sofa is called a parasitic Condor test and if you're gonna do this test in a modern car this test is not gonna be that accurate because in modern cars there's so many computers and control modules that are always gonna draw some current from the battery and if you're gonna disconnect the Buried then those control modules might shut off and the short will disappear temporarily living you do not find the short at all so if you are doing this test in a newer car then you're gonna have to trick the Cask and Peter into thinking that it is time for the cast computer to go to sleep mode in other words we had retained everything off in the car shut all the windows and doors and then lock the car but if he shut the doors and the hood then we can access to the car to the test most cars have door switch somewhere alone this a pillar or this B pillar in this car we have the door switch right here when you close the door this switch get pressed up against the door and that's how the cast can better now whether the DOE is closed or open Stephen is a clamp to hold the switch press down let's say you don't have door switch anywhere around the door then your doors which is inside the door so you wanna use a screwdriver to latch the door locks manually and disable the door switch on the door then you wanna do the same with the hood latch that way we can lock the car without closing the doors if we have a keyless entry then you wanna keep the key fob far away from the car so that the car cannot detect the presence of the key fob then you leave the car for about an hour giving enough time for the Cask and better to go to sleep mode then you go to the fuse box and you uncheck the voltage drop across the fuses now here's what happening if there's a short they should be current grow if there's a current grow then for very small currents the fuses will act as a resistor if the current is controller system then there should be voltage drop from one end to the other so now you're gonna get your multimeter and turn the dial into millivolts then I'm going to test each fuse just long enough to see if the rating goes to zero if you notice a voltage drop across the fuse then that is the circuit with the chart and this way you can find any short in any modern car without even having to disconnect the battery now let's say you check all the pieces but you couldn't find any short but you bury still keep staying overnight or in a few days time then you probably have a very old battery that can hold a charge in you or perhaps your various internal as you're around or you have bad alternator diode testing your Barry and the alternator is very simple and you can easily do it at home I already have two videos on how to test take a battery and the alternator and I'll be sure to link those two videos in the description down below along with all the other tools I have used in this video so you can easily find them also if you haven't subscribed definitely consider subscribing we have cool videos coming up and I'll see you in the next one

Channel: Junky DIY guy

Views: 1,741,483

Rating: 4.8090711 out of 5

Keywords: parasitic current draw, electric short, how to find a short in a car, using multimeter, diagnose electrical issues, short, short circuit, wiring short, battery drain overnight, how to find an electrical short in a car

Id: JFThdbDYL-c

Length: 9min 10sec (550 seconds)

Published: Wed Sep 27 2017