H 111A Automotive Electrical Troubleshooting Training with Vince Fischelli

[Music] well this is the starter kit h1 11a the first troubleshooting trainer in a series of five troubleshooting trainers that we have developed and these have been on the market since about 2000 and have been teaching automotive truck and heavy-duty technicians how to troubleshoot electrical circuits and our experience has taught us that to learn how to troubleshoot you have to do it you can read about it you can talk about it you can watch somebody else to do it but you have to do it yourself to convince yourself that you can troubleshoot vehicle electrical circuits and you can the fact as I'm going to show you with this trainer it's really quite easy when you know how so what you're going to get in the starter kit is a workbook I think it's 71 pages it has everything in it you're going to need I'm going to go through some of the main points but in the workbook when you read about it you'll get a lot more detail so that you can study this circuit and learn the troubleshooting principles without too much trouble it comes with a power board and a lamp board and you'll notice they just snapped together and you pinch it and that connector holds the two circuit boards together connects up a complete circuit and you're ready to power up and begin troubleshooting and testing the circuit now this is a power supply that comes with the kit and you'll notice the power supply plugs in the wall and the red and black lead connect to the red and black notice that one of the wires is shorter than the other now the reason for that is the fact that if this power pack is plugged in it's powered up it has no on/off switch when you plug it in it's live so that means that these two wires are hot if the two wires touch while the power pack is plugged in it will blow the power pack so you say well why didn't you put a fuse in one of the wires and here's some basic electronics 101 if I put a fuse in this wire a small fuse the power pack will be destroyed before the fuse blows so there's no point in using a fuse to protect it because it isn't fast enough if you use a tiny fuse that would blow faster then the circuit won't power up so we had no choice by making one wire shorter than the other it's a reminder that they cannot touch so what we require and emphasize in the workbook hook up the red and black post to the red the red and black wire to the red and black post first then plug in the power pack so let's do that and I'm going to be doing this taking a little bit more time with this first circuit board excuse me because this is your first exposure to it with the other circuit boards you'll have a lot of information already from this training video so you won't need to have such detail so I'm going to connect the wires tie it down tighten it down and then the black wire and you might separate the wires just a little bit to make a little bit easier and then tied down okay now we've connected the red and black wire to the red and black post notice the power pack is not plugged in yet I'm gonna plug it in right now and we are ready to begin troubleshooting I'll put the book aside and I'll bring the meter into the picture so that you can see the readings as we take them and we'll cover several points of troubleshooting that as I said before is adequately adequately covered in the workbook but I want you to hear from me as I point some of these things out so in the event that you have purchased one of these starter kits and you're ready to start using it watching this little short video will help you get started a whole lot quicker okay so now the circuit is powered up it is not on notice the lamp is not lit I'm going to turn the lamp on by adjusting the ignition switch toggle up and you see the lamp comes on now you're going to say well that's pretty simple circuit oh yeah why don't we learn how to troubleshoot with a simple circuit why do we have to learn how to troubleshoot with a difficult circuit that only makes learning the principal's order so I teach troubleshooting the first time with a lamp circuit because it's easier to understand and you realize that as you learn troubleshooting you can troubleshoot a lamp circuit and a DC motor circuit and a relay circuit and a solenoid circuit it's all done the same way so if I can teach you the principles with a lamp circuit and you do it the same way on every other circuit as I'll show you in the other videos that we produce for each one of the circuit or trainers you realize how simple troubleshooting is when you follow a simple procedure which we will illustrate for you with these videos now just to give you an overview of the Power Board the red and black posts are there to receive the red and black wire from the power pack now the black post that is actually the negative terminal of the battery called - bat and that's where you have B - B - is zero point zero zero volt and I'm going to ground of my meter if my leads get untangled here you've ever had that happen you know what I'm talking about you think you got them untangled and then they seem out somehow tangled themselves up while you're talking about something else okay so I'm untangled again I'm going to ground my meter at the battery negative post and I simulate that by using the black post on the circuit board one of the most important things to learn about troubleshooting electrical circuits on a vehicle and what I'm saying is what I'm going to teach you here with the circuit board is exactly what you're going to do on the vehicle the same way and you'll find the problem so you have to ground your meter on the vehicle at - Pat the negative terminal of the battery or in some cases if the battery is unaccessible because it's in a compartment somewhere on the vehicle you can't get to very easily you might have the option of also using the ground of the generator which is the metal case of the generator but the point being you have to put zero point zero zero volt on the black lead when you start measuring circuits so that you get an accurate reading of what you're going to have in the circuit so I put the meter here on the 20 volt range and I'm going to measure first off the voltage between the red and the black post and you see there I have a reading of seventeen point six volts now that power pack is providing a DC voltage in the range of seventeen point six volts which is obviously too high so what you don't see is a regulator circuit on the bottom of the circuit board here you see a regulator transistor some capacitors and resistors and what they're doing is they are taking that sixteen seventeen point six volts and breaking it down to a regulated let's see there we go now I'm going to measure not the black not the red post I'm going to measure the plus back terminal which is a little loop pin that is the B plus terminal the positive post of the battery that little loop pin forget about the red post the only reason it's there is to receive the red wire if I want to measure how much voltage is available to this circuit I grounded battery negative and I measure at the red loop pin and I see this circuit is producing thirteen point six five volts okay now notice that we have two fuses we have an ignition switch a three-position switch the only time the ignition switch is closed is when it's toggled up if I toggle to the center or down the lamp is out the loads not working so I toggle up and the lamp comes on the circuit is now working then we have two sides sorry slide switches s3 and 4s3 is on the voltage side of the circuit s4 is on the ground side of the circuit and you're going to go through exercises in the workbook explaining this step-by-step and the reason for these switches is it allows us to demonstrate how I can control that lamp that load in the circuit by switching voltage off and on and in the workbook it's going to have you measure the circuit and actually see the readings and then we have the switch s4 on the ground side and if I turn it on and off I can control the lamp so what this shows you is anytime you have an electrical circuit there's a load that the circuit is controlling well you can control that load by switching voltage or switching ground so we have both features built in so we can use this later on in some of the other circuit board trainers okay so we mention our B+ and we have thirteen point six four and the circuit is powered up everything is working and I'm going to show you here that using a lamp while it may sound kind of basic to some of you thinking oh I need something more advanced than that well the point being if I took that lamp bulb out and put a solenoid in it or a DC motor which I'll do later or a relay which I'll do with another circuit board or hook up a wire harness they all work the same way you're going to follow the same troubleshooting procedure that we're going to be talking about here let me give you a little quick jump ahead to what I'm talking about here is a circuit it's working is bright as far as I can tell is operating correctly from the visual inspection so what I want to do is test the circuit and see if that sir it is operating properly the first thing I'm going to do is measure the voltage going to the lamp and I call that pin one you'll see that as we go through the different circuit boards I use very much the same terminology to make it easy to adapt to the next circuit and see how it all fits together so I measure pin 1 which is the voltage side of the circuit and I see that the lamp is receiving 12 point eight five volts on the voltage side and then I go to pin 2 which is the ground side and I measure and I find on the ground side I have zero point zero three now I know from those two readings that this circuit is perfectly as operating perfectly and everything is good you ever wonder sometimes when troubleshooting a circuit and you're thinking well is it working as good as it should how would you know do what I just did I call this a Texas two-step I measure pin 1 I have good B+ which I know is going to be twelve point eight five because my B+ is thirteen point six four so somehow seven tenths of a bolt is not getting to the lamp well if you'll notice back up here on the circuit board right below the red post there is a diode and that feeds pin one now notice what I have four readings on the B+ terminal I have thirteen point six four on TP one I have twelve point eight nine this diode is dropping 0.7 volts so when I come down to TP one I have twelve point eight nine when I get to pin one on the lamp I've got twelve point eight five so you can see the voltage side of the circuit is not popping any voltage of any major amount and that's telling me the circuit is working correctly on the ground side when I check pin 2 I see my reading of 0.03 and I go back up here to the minus bat terminal and I'm blocking the meter and of course I have zero point zero zero so the point being the ground sight is good and so by checking the voltage to the load and the ground on the load and getting good readings you know the circus is doing everything it should do if for any reason the lamp is not bright enough when it's got good voltage and good ground it's probably something wrong with the lab like perhaps they put the wrong lamp in the circuit and it has a different variance than what is specified so as a point of reference let me always mention things as I come to mind when you replace a lamp in a circuit make sure you're using the correct lamp because Lance can look alike have the same socket but be a different part number because they have a different filament and that can change the circuits operation if say for example a monitor on the dash is lit up because it senses a brake light is out and you go to the brake light it's working but somebody put the wrong bulb in there and the control unit up and the dash thinks the bulb is bad because it doesn't see the correct resistance so just always use the correct bulb and avoid some of those kind of problems that cause your hair to grow gray before you're old okay so the question then is what's that diode doing there this diode is called a polarity sensing diode notice the painted band on one end of the diode that corresponds to the line in the diode symbol and you'll see that in the book right now the diode is sitting on top of the diode symbol so it's a little bit hard to see but the illustration in the workbook makes it very clear the purpose of that diode is to protect the circuit should somebody hook up the red and black wires backwards in other words if you connect jumper cables to a car with a dead battery and you do it backwards reverse polarity and you turn the key on you could smoke the control units every one of them would suddenly die because you've got the jumper cables backward so what they do is they put these diodes inside the control units so that if jumper cables are ever reversed the control unit will not turn on with the protection diode being present it doesn't let current flow in the wrong direction as it would when you reverse polarity that's explained in the workbook as well okay so let's move down we go to our fuse now these are mental cap fuses we can use both ends of the fuse to measure the hot side of the fuse at twelve point eight nine coal side of the fuse is 12 point eight nine so the fuse is not dropping any voltage and then we go down through the circuit and we're going to do some measurements but the way we do it in the exercises is we have you start by tracing the voltage side at pin one now this tells you you have 12 point eight five B plus getting to the load and I'll go back up to teepee 13 and then I'll go through the connector to teepee seven tp6 the other side of s3 is TP five to this little zero ohm resistor and then up to TP 3 and 2 TP to defuse both sides TP 1 what I have just done is I have traced B+ through the circuit and of course the circuit has no problem a little bit later I'm gonna put a problem in and you'll see how this works when the problem shows up how to find the problem ok now I'm going to trace the ground side of the circuit I'm gonna do this with my right hand pin to the ground side 0.03 that's excellent I go to teepee 14 0.03 I go through the connector see 702 teepee 10 0.02 so you can see I dropped about 10 millivolts in that connector which is perfectly normal you're never going to get connector be perfect they're always going to drop a tiny tiny bit of voltage because there are two pieces of metal pressed together and that will sometimes produce very small voltage drops then I go to teepee 11 and then teepee 12 the other side of this 4 and then the G 101 think of G 101 as your sheet metal ground and then from G 101 we go back up to G 100 think of G 100 as your engine ground notice it's zero point zero zero and at G 101 I had zero point zero a little bit there see it's kind of fluctuating but it's if you hold it tight it's about zero point zero 1 or 0 and then 0 point 0 0 and G 100 so that tells you the wire jumper between G 101 and G 100 is OK and then G 100 is your engine ground but that connects through this cable to the negative post of the battery so I just traced very quickly Volpe signed in the ground side the workbook will take you through this step-by-step explaining various principles along the way that will make it plain and take you slowly so if you're doing this at home the workbook hopefully will answer any question that comes to mind so far since 2000 when this product was first introduced that was 17 years ago I don't think I had two or three calls from anybody saying I don't understand something because the book explains it as good as I could explain it on the written page but I'll tell you one thing that's trip people up the most they start thinking this red post is a positive post of the battery and it's not and I remind them the little loop pin and they say oh okay thank you that's that's the one area where people have called me the most like two or three times in 17 years so this is very well documented for you to study let me demonstrate a couple of things for you you know we talked about the voltage side of the circuit let me take the leads and we're going to measure the voltage drop of the voltage side of the circuit it's in your workbook as well now the voltage side of the circuit is zero point seven nine volts remember this diode is dropping seven tenths of a bowl now the rest of the wire harness the switches and connectors are dropping a tiny amount of voltage actually they're only dropping 0.04 but with the diode included we see a drop of 0.7 nine this is all normal readings because the circuit is working correctly now I'm going to measure the voltage drop to the ground side I'm going to measure from pin 2 back up to the negative post of the bat and I see a total voltage drop on the ground side of 0.03 so that's another way to prove you don't have a problem on the voltage side and you don't have a problem on the ground side simple troubleshooting you know you could take this particular test of measuring the voltage drop of the voltage side which I'm doing right now and I'm getting a reading of 0.79 what would you see on the vehicle I'd say on the average about 0.5 because the diode would be inside the control unit it wouldn't be between the leaves of your meter so I'm looking at here as reading of 0.79 if this were an actual vehicle I might consider that reading to be a little bit high so I would then go to all the connectors and I wiggled the connectors I tap on the fuse box I would do all kinds of things to move the circuit grab the wire harness and just move the harness and see if that reading changes if that reading changes you've got a faulty connection on the voltage side of the circuit I can do this test and I don't need a schematic diagram I don't need anything I just need the meter and the leads have been stretch from the battery positive post to the voltage feed going into the load and my meter will give me the bullet drop reading the workbook will tell you expect about 0.5 volts for most cars trucks and big equipment in some cases it might be a little bit high like 0.7 it depends on the circuit that you do this a few times you begin to realize that 0.79 on this piece of bulldozer equipment is perfectly normal they're all like that but you see if you have an intermittent problem move the harness tap on the switches take the connectors and try to twist them a little bit and if you find one of those connectors being the problem you move it you touch it this reading is going to jump all over the place and you found that intermittent connection and you're done before your buddy has even had time to pour himself a cup of coffee now let's do the same thing on the ground side remove the leads put the test lead on pin two and I go up here to the battery negative oops let me reverse it I'm sorry that it doesn't matter which way did we do it with the digital because it doesn't matter if the reading is backwards it just has a minus sign so I put the ground back to the battery negative post I take the red lead and I touch the ground pin on the load now I'm looking at the ground side of the circuit and I'll take that ground strap and I'll move it and if it starts to cause this reading to fluctuate you found an intermittent problem on the ground side of the circuit now tell you something when you have an intermittent problem it's a nightmare right you've seen them before and you pull your hair out trying to figure out how can I find this intermittent connection I hit a bump it acts up hit another pup is stops acting up well use this multimeter voltage drop principle and you can about validate every connector on the voltage side and every connector on the ground side and find those poor connections so easily it's almost a crime to charge the customer for fixing his car yeah I'm sure okay now let's insert a few problems let's just get right into it I'm going to turn the meter back on I started to take a break but then slide it will just keep on going alright now in the kit when you buy this kit you're gonna get a instructor guide and the instructor guide will tell you what problem to insert so when you go to the workbook and say like you're going to troubleshoot problem number one in the workbook you look up the instructor guide and they tell - what problem to put in for problem number one so the first thing you're going to do is turn the circuit off you can leave the power pack plugged in the red and black leads are still connected to the red and black post so they're safe I'm going to turn this over now you'll notice on the bottom there's a bunch of these little zero ohm resistors and there's one here on the top and I didn't mention it why is the zero ohm resistor it's nothing more than a jumper wire now you know it's a zero ohm resistor because it has a single black band in the center that tells you it's a wire jumper but it's made to look like a little resistor and we have a couple of them here in different places and you will use these from time to time now I want to mention something here if this board is brand new the first time you pull a zero ohm resistor out please pull straight up and it will fight you you'll have to pull kind of hard to get it up I'm going to pull this one out here see now now once it comes out a couple of times the pins loosen up and everything works fine I'm going to insert a carbon resistor into this point and what I have done is I have created a voltage drop on the voltage side now I'm going to turn the circuit on look at the lamp see how the lamp is dim alright now that's a dim brake light you get pulled over by the police for a brake light being too bright to dim so therefore this circuits got a problem now if that lamp were a DC motor how would the DC motor be working right now it would be slow low RPM if that were a solenoid the solenoid would be sluggish if that were a relay the relay might not click or if it did click when it turns on the circuit with the contacts since the voltage drop is on the contact side it would affect the circuit that the relay is controlling so that's what we'll get into when we do the other circuit board trainers later so here we are we've got a definite problem I'm gonna measure pin 1 look at that I've got 5 point 2 5 volts so I already know that this lamp is dim this circuit has a problem because I have low B+ now I'm going to continue on with the ground side just to make sure and the ground side is still zero point zero it was a zero point zero 3 but it's a zero point zero one now because there's less current through the circuit so there's less of a bullish drop due to the lower current flowing through the connections and the wire so I have B plus problem bulky side problem and I'm going to trace it back up the circuit which you will do with the workbook taking it up this way step-by-step that eat the each of these measurements I'm still low I'm still looking for my B plus still low still low still low whoops at test point three I have my B plus twelve point nine one but I go to TP four and I have low b-plus so there is a voltage drop between TP 3 and TP for that's exactly what would happen in the vehicle if you went to the ignition switch and measured the voltage coming out of the ignition switch and you measure that this connector here and you'd see a drop of about seven alone so you know there's a bad problem in that portion of the wire harness or the connector on either end that's troubleshooting it's easy when you know how now let's turn this off I'm going to remove the problem by the way this was a carbon resistor which comes in the resistor bag you get one of these with every kid we have a series of resistors and some zero ohm resistors and this is enabling you to do all the problems that are associated with that circuit board now you got to put that zero home back in again to you three and I just did that I bent that lead take your time you got plenty of time here okay so everything's back to normal I removed the bad connection I checked pin one my voltage is back to normal again I fixed the customer circuit and the service advisor is still writing up the ticket that's how fast it goes once you know how what you're doing okay now let's throw a problem in on the ground side I'm going to turn the circuit off and this time I'm going to pull out you thirteen by the way the jumpers on the bottom are numbered and we call them u jumpers u is four under the circuit board now while I'm putting problems in to demonstrate if you're studying this at home find somebody around you that can put these problems in for you anybody can do it just they know which jumper to pull out because the book the scepter guide tells them they insert a resistor in there like I'm doing and of course I'm on camera so it's not as easy alright so I put a resistor in there turn it back over now you're ready to come back you didn't look while they did that for you so you don't know if it's an open circuit or a voltage drop you turn the circuit on and up the lamp is dim so I've got a problem in the circuit well is it on the voltage side of the ground side let's go to pin one well I've got good voltage on pin one so my voltage side of the circuit apparently is okay let me go to the ground side and oh boy I've got seven point six five bolts on the ground side and it should be zero point zero three there definitely something wrong on the ground side so I trace out the ground side to go to teepee 14 still high and teepee 10 across the connector still I teepee 11 still high teepee 12 the other side of switch s4 seven point six three I go to G 101 aha look at that my sheet metal ground is seven point six three that comes from G 100 I go to G 100 I'm zero point zero zero so that ground strap between the engine block and the sheet metal is corroded causing the voltage drop and it's as simple as that turn the circuit off remove the resistor from their circuit which created the voltage drop and drop the little zero ohm okay I found the little zero ohm and fell on the floor and put that into you 13 where it belongs at zero ohm resister restores the circuit to normal operation I confirm normal operation by having B+ on pin 1 and a good B - on pin 2 so you see this is the kind of troubleshooting that we we do there's about 33 pages in the workbook of going through a lot of exercises and then you start troubleshooting a total of 28 problems with open circuits and voltage drops and that's how you learn how to troubleshoot you practice you do it over and over and you build your confidence up and no matter what problem we put in the circuit by following these simple troubleshooting techniques you identify quickly if it's a voltage side or ground side problem or possibly even both so you have to just have a procedure and do some practice and do some troubleshooting and then all of a sudden you realize that you can indeed troubleshoot a circuit now we have some other problems besides opens and voltage drops and you're going to see this in the workbook I'm skipping over some of it I don't want to spend a lot of time with such detail because you need this the trainer to actually practice it I'm going to show you a technique that I find very effective for finding shorts to ground so I'm going to pause the video for a second here and get set up for that and then we'll pick it up and show you how to use an ohmmeter to find a short to ground okay we're back and we're going to demonstrate how to use an ohm meter to find a short to ground now we all know shorts the ground can be very difficult to track down especially in some vehicles where you have shorts in the back of the vehicle and you're up in the front of the vehicle or vice versa or just trying to access the cables and connectors it's awkward at many times so let me show you how to take an ohm meter and let's see if the circuit has a short or not first we're going to unplug so I'm going to disconnect the power pack there it is it's unplugged now I can take the red and black wire off and the power pack is safe and I'm going to go back to the ground on the - bat now if you're doing this on a car what you would actually do is take the red the battery positive cable off the vehicle off the battery so the circuit is sitting here without any voltage anywhere in the circuit I'm going to put the old meter on the 200 ohm range and the principle is and you'll read this in the workbook so it'll walk you through it you have four problems short to ground practice I'm going to close the switch and connect everything together so as if the circuit were on and I'm going to take my fuse and lift the fuse up that simulates the fuse is blown now I'm going to take this ohm meter and it's grounded at - Pat and I'm going to measure the cosine of the fuse and I see ten point six ohms to ground well that's because the bulbs in the socket I'm going to take the bulb out now at that the bulb has been removed so the bow was was connected to the circuit and the ohm meter was reading through the boat so what you have to do is you have to disconnect the load so now this voltage side of the circuit is sitting here it's not connected at either end the fuse is disconnected it from the the power side and the lamp has been disconnected to remove it from the ground side so the hot side of the circuit is existing now in the vehicle going from the coal side of the fuse I have an indication of high resistance infinity so therefore there's no short to ground now I'm going to put a short to ground on the circuit you're gonna see this because you're watching I'm gonna make the chute the socket itself shorted I put a short across the socket now when I go to the now now the fuse is blown so the circuit is actually shorted to ground I go to the coal side of the fuse and I see a low resistance reading so I'm seeing my short to ground with my own meter so now I'm going to open the switch okay it went to infinity so therefore the short to ground is not in the switch it's on the other side of the switch alright now I'm going to go to s 3 if that were a connector just pull it apart okay so the reading goes back to infinity so the short is on the other side of s 3 there it is again and I come down to tepee 13 and I can take this little zero ohm resistor out in j-1 and check their so it's good but when I go on the other side I see a little reading and the only thing left in the circuit is the wire from j1 be to pin one or the socket itself so there's the problem using an ohm meter trace is short to ground it's quick and it will show you what part of the circuit has too short to ground and which parts of the circuit are not shorted to ground you

Channel: Vince Fischelli

Views: 13,294

Rating: 4.8461537 out of 5

Keywords: H-111A Starter Kit, electrical circuit, Vince Fischelli, test voltage, amps, troubleshooting hands-on, how electrical circuits work, measure amperage, how electrical circuits fail, measure voltage, measure resistance in ohms, open circuit, voltage drops, shorts to ground, tracing B+, tracing B-, voltage side of circuit, ground side of circuit, ground problems, Texas Two Step, TTS, TTS-1, TTS-2, voltage side problems, ground side problems, truck electrical, training

Id: wIWic4sGgvA

Length: 44min 32sec (2672 seconds)

Published: Tue Sep 19 2017