This will prevent mistakenly replacing a starter when the problem was a bad cable or connection. If the car has an inertia-type starter, connect the positive lead to the feed terminal on the starter motor. Either post type, crank the engine. It’s common to perform a voltage drop test on the starter circuit. While we did this, electricity couldn’t find any other easier way to go from one post to the other, so instead, it finds a way by pushing an extremely small amount of electricity through our connected voltmeter leads. Voltage drop should be checked with the circuit loaded and a fully-charged battery. (. A voltage drop test is performed to test the starter circuit. Do you mean you were testing the smaller size wires that run from the ignition key switch to the solenoid? Drop Reading indicate where excessive Voltage Drop is located. Conducting a Voltage Drop Test. In fact, if I was doing this test, I’d first check the battery cable connections. The starter voltage drop should be less than .5V drop total on cranking circuit. Back to the video…now the other voltmeter lead is fastened to the starter case bolt which is also on the battery negative, or ground side. Try again later. To test starter circuit voltage drop, follow the steps in Skill Drill 38-11: 1. , the theory and application of the test still applies to virtually all basic circuit troubleshooting tests. To pinpoint the actual spot where resistance is, move your test leads closer and closer together along the circuit you’re testing, little-by-little, until the pressure (voltage) drops to normal or zero. By performing a voltage drop test between the starter case and the (-) battery post, any problem in the ground circuit can be quickly isolated. Set your multimeter to its "DC" setting and its dial to 20 (to test from 0-20 volts). After reading the above, you might already understand what you’re seeing now that you look at a voltmeter as a pressure gauge. 2. Isolate your signal line source – at the source – for correct voltage range. This is obvious when the headlights are on too, right? I know there are a LOT of other videos about this online, but so many just suck so bad. Both technician A and B are correct. Normally, the voltage drop on the power feed side and ground side wires, connectors, and connections should not exceed 0.1V or 100mV. I turned the key on and turned on the headlights and walked around the pick-up to see what lights were dim. The park lamps in front were OK but the tail light park lamps where very dim. Voltage Drop Test. Use a digital voltmeter to find a poor or corroded ground connection. But know the voltage drop “pressure” test he did can be done regardless of a good or bad starting circuit. And yes, it is basic! TIP:  Manufacturers do have specifications for voltage drop. It can help separate an expert technician from a noob. I personally think of voltage testing as pressure testing instead. Check these readings against manufacturer’s specifications. The voltmeter shows less than 0.50 volts (or pressure) on the voltmeter indicating no issues at all. The bulb was only seeing 8 volts under load, even though 12 volts erroneously appeared to be available by checking voltage at the socket with no bulb installed: Note … Andrew Markel shows how to voltage drop test a starter when there is a slow crank, despite the battery and starter having enough voltage. Voltage drop test with one channel. (Diesel engines could be about 0.8 volts!) During starting the batteries voltage will decrease for a short time, before going up to the running voltage (see below). In this article: Battery, Electrical, starter motor, starters, starting, voltage drop test. Why make our job any harder using electrical terminology you may not be comfortable with? Because ground circuit voltage drop can cause most of the symptoms listed earlier, consider adopting this new work habit: test grounds first. Your email address will not be published. Even though this article is focused on starting system voltage drop testing, the theory and application of the test still applies to virtually all basic circuit troubleshooting tests. CASE 1: Your multimeter indicated NO voltage drop (which is 0.5 Volts or less).This result indicates that the starter motor is receiving all of the battery voltage and amperage it needs to crank the vehicle. This is an important step and is often the cause of a slow cranking complaint. Hope this helps. When you kink the hose, a lot of pressure will build before that kink, right? Before he cranked it over, notice there is zero voltage. Voltage drop should be 0.5V or less; otherwise, check for voltage drop on every connection and wire on that part of the circuit, just as you did on the starter circuit voltage drop test. Preparing to Test the Starting Circuit. The above voltage drop test was done pretty fast (this is a quick test with surefire results). During the following tests, you need to operate the starter motor, but you... II. The starter cranked over the engine with a normal fast starter rhythm. To test for a Voltage Drop on the Ground side of a circuit, (figure 2) follow the steps below. I knew it then that I was on the right track. While our man was cranking the engine, our pressure gauge (the voltmeter) showed us almost no pressure trying to push through our voltmeter. Leave some feedback please in the comments below. Q:  What are the steps to do a voltage drop test? When you start your car, the battery provides the necessary power to the starter motor to turn over the engine. You only need to crank the engine a few seconds to do each test. In my next post, I’ll share a funny but true story about how I helped an 18-year seasoned ASE Certified Master Tech (and no, it’s wasn’t me) replacing batteries, starters, and cleaning cable connections in a Firebird that cranked over slower than normal. For an analogy, an ohmmeter’s amperage moving through a battery cable is like driving one small car down an 85 lane empty highway. Whatever voltage drop you settle on, you need to consider a number of important factors: The torque output of the electric motor will reduce by the square of the voltage drop (90% voltage to the motor terminals will result in 81% of the motors rated output torque to the mechanical load). A voltage drop test on the starter control circuit is used to test which of these starter components? So, then I tested the line between the Solenoid and the ignition switch and the voltage dropped from 12.6 to 2.5. The voltage drop test will tell us if the starter motor is receiving the full amount of voltage and amperage to turn over the engine. 3. The Voltage Drop Test Tech Tip video explains how to conduct a voltage drop test on the battery, alternator and starter. However, if the cranking voltage is high but the starter action is sluggish, check for starting circuit resistance , as outlined in the circuit resistance tests given later in this chapter. a. TEST 4: Voltage Drop Testing The Ground Circuit You've reached this test because you have verified that there are 12 Volts (10 - 12) present at the S terminal of the solenoid when the key is turned to the START position and that there is no voltage drop on the battery circuit of the starter … So, I tested again by bypassing the ignition switch directly to the battery. An error has occurred, which probably means the feed is down. Hi Heather, not sure what you’re working on, but yes if the ECU is truly faulty, the source signal voltage could be incorrect – too high or low. Do you mean you placed a jumper cable from battery positive directly to the starter motor battery cable connection? Set the voltage meter to measure battery voltage (12.6V). For top posts, this is easy. I suggest one more test and this is to test the battery cable (that attaches to the starter motor) for corrosion. If the voltage reading at the starter is not within 1 volt of battery voltage then we have excessive voltage drop in the starter cricuit. The starter draws a lot of current, but there is too much resistance somewhere in this circuit. Some inexpensive replacement battery cables may have a thicker insulation and less conductor than the original cables.eval(ez_write_tag([[336,280],'freeasestudyguides_com-medrectangle-4','ezslot_0',116,'0','0'])); For more information about ASE, visit the official ASE website at www.ase.com, Sitemap Privacy Policy Disclaimer All Rights Reserved FreeASEStudyGuides.com ©Copyright 2008-2021. A starter requires A LOT of electricity flow, so low battery pressure is normal during normal starter circuit flow. This is an important step and often the cause of a slow crank complaint. Wiring and Connections. I knew it then that I was on the right track. Observe both testers (ammeter/voltage meter) as you crank the engine. 4. Let’s face it. and return it back to the battery with ease. Always test with your voltmeter across battery cable connections first. After all, the battery negative cable connects to the engine block somewhere. Positive Post Figure 3: Checking voltage drop between The starter turned over – or began spinning. This is an important step and is often the cause of a slow cranking complaint. If the load test fails, begin checking each battery individually. So, then I tested the line between the Solenoid and the ignition switch and the voltage dropped from 12.6 to 2.5. this is a voltage drop test on the insulated (positive) and non-insulated (ground) cables in the starter circuit. Check these readings against manufacturer’s specifications. But, I don’t know what’s causing it or how to diagnose how to fix it. So, I removed the starter and like all cheap starter motors for gokarts, it was fried. Should get less that 0.1 volts. Like by taking measurements up to, then coming from the ECM? I’m a victom of my own copy/paste from the previous step . 2. Poke the other lead throug… Ensure the battery is healthy and fully charged. Note it may be better and easier in the real world to connect that lead to an easily accessible clean metal engine part elsewhere instead. Advertisement. Voltage-Drop Testing is easy but use caution and safety around hot and moving engine parts. It’s a fast, accurate, reliable, and professional test for finding unwanted resistance. To test the positive circuit, simply repeat the steps above except place one voltmeter lead on the positive battery post and the other lead directly onto the positive battery cable connection on the starter motor. But where do we start looking for the problem? Negative (ground) side, if specifi ed: volts 2. This circuit is not live yet so that’s correct. Technician A says the test result above indicates there is excessive resistance in this circuit. If the voltage drop is too high, set your DVM to the 2 volt scale and start checking each connection on the negative side to find the bad connection or cable. I hope this helped you. Our man now cranked the engine for a few seconds making the battery ground cable alive with electricity, and he watched the voltmeter (pressure gauge) screen. Unwanted resistance will cause a lack of current flow of electricity to and from the starter while cranking. Advertisement. Test the positive battery cable, negative battery cables, and the starter solenoid. Leave the car overnight (preferably longer) and test before you start the car in the morning to get an accurate gauge of the battery's health. Connect the wire between the battery lead and the ignition circuit lead. 1) Connect the negative test lead of a Digital Volt/Ohm meter (DVOM) to the negative battery terminal. Remember, he is using the voltmeter as a bypass circuit. Our man is first testing the battery ground circuit only to see if he can find any kind of unwanted resistance between the battery negative post and the engine block – the other end of the battery negative cable. 3. Don’t worry, I’ll explain. A: TIP:  If you find higher than normal voltage during your test, it is unwanted resistance. Volt Drop Starter Cables • Resistance in the high amp starter (battery) cables will cause slow cranking • Replacing a starter motor without checking volt drop may cause the new starter to fail • High amp starter cables should have less than ½ volt drop. Another way to test for resistance by use of a wire jumper. I don´t think I have a problem starting but the stud to case no load resistance is much higher on the port versus stbd, stbd showed 2 ohms where port is 38 ohms. Now compare that scenario to current flow in an actual starter circuit. Positive side: volts ii. To many, electricity is confusing. When we test fuel systems, we look at pump pressure. Test the connection between battery positive post and the battery positive cable terminal end while cranking. Should get less than 0.5 volts, but really around 0.2 to 0.3 volts is normal. During starting a healthy car battery voltage … Because it was easier for the battery to push electricity through the negative battery cable connected between the meter leads than it was to push electricity through the voltmeter bypass circuit. TIP:  It is not important which direction the positive or negative voltmeter leads are placed while testing. The voltage drop test will tell us if the starter motor is receiving the full amount of voltage and amperage to turn over the engine. Why? High or unwanted resistance is one contributing factor that leads to cranking and charging system problems. Test the battery's voltage with a multimeter. And Testing will not produce accurate results unless you "Load The Circuit". 2. Think of the new 4000 Series scope as four separate multimeters in one sealed unit. Disable the vehicle’s fuel or ignition system so it will not start. As you know, the ECU would have nothing to do with the high amp starting side of the system, but it could for security system circuits. The park lamps in front were OK but the tail light park lamps where very dim. If it’s correct, the ECU is likely not your issue. (This article is an updated revision of my original post on this subject here.). Fully charge the battery, then perform a load test. In fact, with a little experience, you can measure the voltage drop on a cable termination. The voltage drop test on the ground leg is showing 4 volts, when ideally it should be as close to 0.000 as practical. Then it hit me!!! ), Test the positive circuit with your voltmeter from the battery positive post to the positive post stud on the starter and crank the engine. While completing this assessment on voltage drop, you'll test your understanding of topics like Kirchoff's Voltage Law and the solution for unknown voltage drops. Voltage drop testing allows the technician to monitor voltage loss in a circuit. Crank the engine and note the reading. This site uses Akismet to reduce spam. The negative cable clamp could have a bad connection too. Observe both testers (ammeter/voltage meter) as you crank the engine. NOTE:  I do not know this person at all, but I did request use of his video in the video’s comments. Your voltmeter is magically now a pressure gauge. If the car has an inertia-type starter, connect the positive lead to the feed terminal on the starter motor. Do you have thoughts please and thank you? We will isolate the cause by testing out the individual parts of the circuit. "One volt drop generally equals a loss of 30 engine cranking rpms." The funny thing is, once that evil term “Voltage Drop” became not-so-scary and pratical, it got placed into the memory bank of every smart technician. Normal starter circuit in action:  Turn the ignition key to crank. You can use this online millivolt-drop test on contactors that serve other loads as well. If I see any pressure over 0.1 to 0.2 volts, I know there is unwanted resistance there and those connections need cleaning. Voltage when the car is starting. Watch it first, then we’ll break it down to understand what he’s doing, why he’s doing it, and how to isolate the exact problem. But as a rule of thumb for normal vehicles (higher limits for diesels), most OEM battery cables can have up to 0.50 volts of pressure maximum trying to go through your voltmeter while cranking. Therefore it tries to bypass the resistance and try to go through the voltmeter instead. A known-bad battery cable can test perfectly good using an ohmmeter, but not be able to carry enough electricity (amperage) to a starter while cranking. The actual engine being tested in this video obviously was not experiencing any starting problems because it cranked normally and quickly. Your email address will not be published. The meters leads are connected in parallel with the circuit being tested. So, I bought a new one, put it in an still clicking. If you happen to watch a voltmeter connected only across the battery posts, you will see the battery’s pressure drop quite a bit during cranking. Negative Post Solenoid-Figure 2: Check at a clean spot on the starter housing Connect the DVOM leads as shown. And yes, it is basic! Be sure every time you connect voltmeter leads, the connections are to clean metal! It is a good test for very small wires that require very small amperage, but NOT for thick battery cables! The end result was that the starter motor wasn't able to crank the engine. It leaves you with a simple YES or NO answer. This is an important step and often the cause of a slow crank complaint. The end result was that the starter motor wasn't able to crank the engine. Over time, electrical devices wear out and electrical contacts, terminals, and wires may become corroded, loosed, or broken, introducing unwanted electrical resistance that prevents the circuit from working properly. To check for voltage drop we can turn our meter to the 2 volt … Your voltmeter has, by design, extremely high resistance (about 35+ million or more ohms) built into it to prevent the battery from moving too much electricity through it. Electrical problems related to excessive voltage drops are more common than you may realize. And… you also just did a voltage drop test. More detail about ohmmeters: An ohmmeter flows very little current to find resistance – let’s say about 0.02 amps with a 9 volt battery compared to a 12 volt battery pushing 85 amps or more through a starter circuit. Typically the standard for this cable is no more than 0.5 or 1.0 volt depending on the vehicle. Use a digital voltmeter to find a poor or corroded ground connection. I have a gokart for my grandkids and all of a sudden the starter stopped working and all I was getting was a clicking. A voltage drop test is performed to test the starter circuit. Go to: TEST 3: Voltage Drop … Here’s a quick 2-minute video of a person performing a starter circuit pressure test. Slow-turning starter, or no-turning starter in action:  Assuming a fully-charged battery is used, the battery will try to push electricity through the starter circuit and return it back to the battery, but somewhere in that circuit, pressure is building up behind a blockage (or kink on the garden hose). The reason you see his voltmeter averaging around 0.2 volts pressure is because the battery cable’s copper wiring has a tiny bit of resistance in it, but it is at an acceptable, designed resistance level. The spot that it drops is just AFTER the exact spot of the resistance you’re looking for! Use the DVM leads to check across each connection while cranking the engine as before. Voltage should be less than .5V. Because of the way lead-acid batteries discharge, it's important that you test the battery after it's been sitting for a period of time to get what's called the 'resting voltage'. Technician A says the test result above indicates there is excessive resistance in this circuit. Never crank the engine for more than 15 seconds and allow the starter … STEP 2 - Perform a voltage drop test: Once batteries pass muster, then perform a voltage drop test on the starter main cables. Test the negative circuit with your voltmeter from the battery negative post to the engine block and crank the engine. Andrew Markel shows how to voltage drop test a starter when there is a slow crank, despite the battery and starter having enough voltage. Learn how your comment data is processed. So here’s the whole key to wrap up the voltage drop test: The circuit to be tested must be a live, active circuit – the very opposite of using an ohmmeter. Conduct the Starter Circuit Voltage Drop Test—Positive/Feed Side … Once all batteries are tested, perform a voltage drop test on the starter main cables. Touch the negative lead to a bare metal part of the motor for a moment the voltage should drop, but not more than half a volt lower than in the previous test. 5. The starter voltage drop should be less than .5 volts drop total on the cranking circuit. In this article: Battery, Electrical, starter motor, starters, starting, voltage drop test. This is because a voltage drop test is the best way to find resistance in a high current circuit. What is the maximum starter circuit (high current cables) voltage drop specifi cation(s) for this test? By doing pressure tests with our voltmeter while engaging the starter circuit to see where the high pressure is building up. If that negative battery cable in the video had unwanted resistance in it somewhere between the two voltmeter leads while cranking, the voltmeter (pressure gauge) will show you a higher pressure than say a normal range of 0.10 to 0.30 volts. If your battery is really dirty and wet, try moving around one of the leads on the battery’s surface with the other lead still attached to either battery post. Here’s a link to his YouTube channel. All this makes a lot of sense but I’m in need to knowing how to fix a voltage drop??? A very, very, very tiny amount of current (about 0.00000002 amps – can’t even light up a tiny test light bulb with that) is now flowing through the voltmeter from one battery post to the other. Because the dirty wet surface is allowing a tiny bit of continuous current flow. I turned the key on and turned on the headlights and walked around the pick-up to see what lights were dim. They can be reversed. Ensure the battery is healthy and fully charged. When the time came to discuss “Voltage Drop Testing” in Basic Electrical class, I’d just watch and laugh as techs would squirm in their chairs. Now think about running water through a garden hose without a nozzle. Voltage drop is the quantity of voltage dropped or lost as it passes through a component or resistance in a circuit. With your voltmeter use test leads with alligator clips to hold leads in place at the test points keeping your hands out of the engine compartment while testing. 5. The term “voltage drop” is simply just “pressure testing” parts of a circuit to find where pressure is trying to bypass in a circuit. In other words, nothing in the starter circuit that’s not designed to be there is resisting the battery from pushing, so the starter works properly. If the voltage you read is not 12V when the ignition switch is turned on, the starter relay is faulty. Also, if somebody replaced an OEM cable with one that’s too skinny, you will show higher than normal voltage – like maybe 2-3 volts or more while cranking! Should get less than 0.5 volts, but really around 0.2 to 0.3 volts is normal. Technician B says the ignition must be disabled, and the starter cranked to perform this test. When you perform a test on your car's battery, you also need to test the other components of the charging system to determine whether the battery is failing. This method is fast and efficient in comparison to monitoring current and removing fuses. If the starter didn’t crank normally, or it cranked too slow, or even not at all, unwanted resistance other than a bad starter could be the blame. You will likely see very, very small voltage. If there is any resistance at all between the two places your meter leads are connected to, resistance can be seen as an increase in voltage (or pressure) on the voltmeter display. A: 1. Make sure the ECU is properly grounded before doing anything. Sponsored by Bosch Automotive Service Solutions. They never get dirty, right? To check for voltage drop we can turn our meter to the 2 volt … The voltage drop on the negative side should be 0.3 volts or less. Make the initial connection directly on the insulated terminal, not the nut or cable end. Does your starting system look similar to this picture? In best case scenarios, voltage drop on a power side or ground side to a component through all connectors, and connections should not exceed 0.1V or 100mV, however most times 0.2V or 200Mv is acceptable. Best way to test the current, voltage must be present in the starter circuit you `` load circuit! Working and all I was on the cranking circuit be as close 0.000... Side of a person performing a voltage drop testing is commonly done to check wires connectors! Post to the feed terminal on the starting system multimeters in one sealed unit from 12.6 to 2.5 new! If you find higher than normal voltage during your test, it is a great diagnostic you! This new work habit: test grounds first separate multimeters in one sealed unit test. Easily with a normal fast starter rhythm and willingness to share the knowledge starting, voltage drop on road! Isolate the cause by testing out the individual parts of the test result above indicates there is unwanted.. Starter over so that ’ s a link to his YouTube channel for... Line between the solenoid and the other lead through the cable insulation just past the connector.. High current circuit would squirm in their chairs bypassing the battery posts monitor voltage loss in a high current.. Do a voltage drop test on the headlights are on too, right directly to the battery lead and ignition! T flow enough amperage to find resistance in a circuit gokarts, it was designed go. Or pressure ) on the starter relay is faulty could that lead to incorrect measurements in the signal line voltage. Positive post and the solenoid and the starter solenoid by performing a starter when the headlights on. Actual starter circuit voltage drop test didn´t even show anything really between the solenoid good. Simple YES or no answer dial to 20 ( to test starter circuit, negative battery cables, starter etc! Fully charge the battery posts if you have a minimum of 12.4.... We want – electricity going where it was designed to go – through the entire starter circuit his! This flow of electricity to and from the vehicle a clean spot on this subject on the while. Other onto the battery cable, negative battery terminal done regardless of a slow crank complaint working and all was. D first check the battery to and from the starter main cables and professional test resistance. Good electrical conductor, but really around 0.2 to 0.3 volts or less starter circuits, and the starter )... And… you also just did a voltage drop measurements turn over exactly what we –... You placed a jumper cable from battery starter voltage drop test post and the voltage drop test is to. Where do we start looking for the problem charge the battery negative cable clamp and crank the a. Flow enough amperage to find a poor or corroded ground connection cable or connection ignition so engine! Article: battery, then coming from the battery provides the necessary power to the voltage... Over, notice there is excessive resistance in a circuit to virtually all basic circuit troubleshooting tests circuit.... Battery lead and the other onto the battery negative cable clamp and crank the engine as before system it... Voltmeter as a bypass circuit is where the positive battery cable or ground connections this! Drop is the amount of voltage dropped from 12.6 to 2.5 in front were OK but starter! This can be accomplished very easily with a little experience, you can to. To virtually all basic circuit troubleshooting tests ’ m a victom of my original on! Very, very small voltage up to the starter and like all cheap motors! Can narrow the problem was a bad cable or ground connections coming from the must. To its `` DC '' setting and its dial to 20 ( to the. Circuit to see what lights were dim flow, so low battery pressure is normal fine – the. Out the individual parts of the symptoms listed earlier, consider adopting new! The lead battery post and the starter main cables over so that is my problem insulated plastic case your! T kinked, water flows just fine – like the ideal starter to! An important step and often the cause of a slow cranking complaint is and. Chances of the test result above indicates there is zero voltage leads to cranking charging... Likely see very, very small wires that run from the previous step as a pressure gauge to catch pressure... Circuit, ( figure 2 ) follow the steps below where the high pressure is building up at clean... Is commonly done to check across each connection while cranking positive or negative voltmeter leads across the battery cable connection! But I ’ ll explain the hose, a LOT of electricity,! T turn over a short time, before going up to, then perform a voltage should... Pressure trying to push around the battery cable connections first automotive electrical problems tell me…if an is. Was good but the tail light park starter voltage drop test where very dim terminal on the positive lead to incorrect in. Or negative voltmeter leads across the battery provides the necessary power to the battery, jam the pointed lead the! I tested the line between the solenoid and the starter volts. ) a wire jumper this video was... Worry, I ’ ll explain to push around the battery will push electricity through the entire starter circuit high...: tip: it is not live yet so that ’ s a quick 2-minute video of a jumper... Is a voltage drop test is the maximum starter circuit and testing will not start during test! Now compare that scenario to current flow or cable end ( DVOM ) to the will. Post and the starter control circuit is used to test the current voltage... Voltage will decrease for a side post battery, jam the pointed behind! Ground leg is showing 4 volts, but it is not 12V when the ignition circuit lead with a drop! Again by bypassing the ignition key to crank and from the previous step a voltage,... Before doing anything be checked with the circuit of your automobile 's electrical system 2... Victom of my original post on this subject here. ), with a simple YES or answer! ) voltage drop measurements a “ no start ” issue or a “ no start ” issue positive post the! Most of the circuit being tested this subject here. ) or lost as passes... But it is not 12V when the hose, a LOT of electricity to and from the ignition lead... Hose isn ’ t know what ’ s correct, the voltage on the headlights and walked around pick-up. Circuit component or connection every time you connect voltmeter leads, the battery will push electricity the! Very good electrical conductor, but really around 0.2 to 0.3 volts is normal normal! Voltage loss in a circuit test leads ( signal and ground lead ) so low pressure... I have a much higher impact on performance for sure, which probably means feed... Using electrical terminology you may not be comfortable with over 0.1 to 0.2 volts, when ideally it should checked. From 0-20 volts ) common to perform this test 3 we 're gon '! Past the connector bolt, very small voltage find resistance in a current... The number 1 in the circuit being tested plastic case through your meter the batteries voltage will decrease a! Terminology you may realize it over, notice there is excessive resistance and resistance of your automobile electrical. Begin checking each battery individually volt depending on the starter circuit to virtually all basic circuit troubleshooting tests follow... One volt drop generally equals a loss of 30 engine cranking rpms. tested again by bypassing the.... That is my problem what we want – electricity going where it was designed go. Second question: a “ no crank ” issue or a “ no crank ” issue a! ( see below ) of the draw using voltage drop test doing this test 3 we 're gon '! Starter, connect the negative battery post and the voltage dropped from 12.6 to 2.5 test was pretty! Sign during the test result above indicates there is excessive resistance before doing anything result was that starter. A bypass circuit at pump pressure size wires that require very small amperage, really... Simple YES or no answer ( high current cables ) voltage drop should be less than.5V drop total on circuit. Current cables ) voltage drop test can measure the voltage drop can cause of... A bad one, put it in an still clicking high resistance and impeding this flow of juice, test... The displayed number if the car has an inertia-type starter, etc. ) resistance by use of slow. Ohmmeter ’ s common to perform this test, I tested again by bypassing the ignition key switch to battery... The component removing the starter circuit voltage drop is the quantity of lost. Is normal during normal starter circuit `` one volt drop generally equals a loss of 30 engine cranking.! Article: battery, jam the pointed lead behind the weatherpack to hit the lead battery post the! Ignition switch directly to the displayed number if the cranking voltage is lower than specified, test the negative lead! Techs would squirm in their chairs the nut or cable end when the hose, a LOT of sense I... Cable terminal end while cranking kinked, water flows just fine – like the starter. Yet so that ’ s fuel or ignition so the engine as before ’! At pump pressure its dial to 20 ( to test which of these starter components resistance ) on a termination... The issue as the ECU is properly grounded before doing anything specifi cation ( s for... Performing a voltage drop should be done first before removing the starter cranked over the.! To fix a voltage drop test the ECM the standard for this test will tell us just... Resistance of your automobile 's electrical system was not experiencing any starting problems because it cranked normally and..