This is a video tutorial on how to use a test light to help diagnose automotive electrical problems. If you have any further interest please visit www.2carpros.com *Disclaimer: Please use all safety precautions
Thank you for your easy and quick video lesson. I just got my first tester today and had questions as to when to switch from the positive and negative cables of the battery - you answered them which I am so thankful for. Tomorrow is going to be a really fun day because with my light I can now go through all of the electrical and find out more about what is going on with my vehicle.
THANKS! i missed that part - Only notice when saying attach test light to Neg. of battery re: Fuel Injector. 2:29 guess depends if Power is constant on - or know to turn on. twisted understanding tells me it's not my forte'. lol I DO Know website does have info on my car or same engine, when others don't. Cheers!
Because people like me have liked playlists. Giving a video a dislike is a way of helping the video without wrecking my playlist. RU-vid doesn't care about dislikes vs likes as the algorithm just looks at the total.
I don’t consider there is anything wrong with me except my severe lack of auto electrical knowledge. My gripe for this video is; after connecting the probe to the positive terminal, where do put the tip to find a bad ground?
This is one of the clearest, most concise videos I have ever seen dealing with electrical diagnostics and general application of a simple tool. Thank you. Thank you for the information and thank you for not extending your video with filler. A A A A A++++++++
Testing for ground like you say, connect the probe to positive, then where do I put the tip? On the fuses, wires? A bit more info would be helpful for a novice.
My abs pump clip isn’t working and I think I have a brake in the wires somewhere Some if the pins light it up some don’t And i dont know if it means it’s good or bad
I recently purchased a tester light and mine came with a red coloured clamp and I have seen other tester light models with a black coloured clamp.Why are the two different from each other? I understand that one is positive and one is negative just like a battery but don't understand why different makers make them this way?
also test lights may not let current thru. i found out after testing a small electric motor on my tractor. i knew was working. remove test lite run str8 wire and it was fine. even tho the light would light showing working condtion
I'm bit late, but for anyone else wondering, no they're not the same. These testers rely on having an external power source run through them to light up the lamp, usually the car's own battery. When he was checking the alternator for example, that positive connector is wired through to the fuse box and eventually back to the battery positive post. And since you have the tester wire connected directly to the battery negative post, or another metal ground point which is connected back to the battery negative post, then you have a completed circuit from battery positive, through the alternator, through the test light and back to battery negative - hence the test lamp lights up. If you probed that alternator where it should have positive voltage and it didn't light up, then you would know there is not a good 12V at that alternator point. There is likely a problem in the wiring/relays/fuses between the alternator and the battery positive. So you can choose another test point in the middle (say at the fuse box) and continue narrowing down precisely where the fault lies. Whereas a continuity tester (I've only used the continuity function on a multimeter) will rely on its own internal power source (e.g. multimeter batteries) to send a small voltage out one probe and look for it coming back in through the other probe. Hence if there is a complete circuit without any broken wires or switches in the OFF position then it can determine continuity (completed circuit). And you can test continuity through a simple length of wire, a switch (in the ON position), a metal cutlery knife, anything that will conduct electricity. It doesn't need whatever you're testing to be carrying a voltage or even be connected up to anything else. In fact if you just touch the two multimeter probes to each other it will indicate continuity. Whereas if you did that with these automotive test lamps nothing would happen since there isn't any power source. Once it is able to test the level of resistance (Ohms), then usually below a set Ohms value the multimeter (on continuity setting) will beep or light up to show a very low resistance path has been found. Bad connections can still have a complete path / circuit but if they have high resistance (like due to corrosion) then it may show an Ohms reading but not low enough to trigger the continuity indicator. In that case you should still be able to see there's a problem because of high or fluctuating, unstable Ohms readings.
If the light goes on it means the connection is good. If the light don't go on then there is a short, meaning a wire is bare and touching on metal causing an interruption in a continuous circuit.
Ok question I’m trying to figure out my wiring issues for my 1990 GMC Sierra. It has headlights but all the other lights mainly on the back are acting weird for example with key on it has both blinkers front and back but when you turn headlights on nothing on the back works. I used test light on it with parks on and every spot on plug lit up even though I only had parks on. Then I saw this video and hooked my test light up to the ground on my battery and everything is lighting the tester up even if I touch my fender. I hooked up tester to positive side and it won’t light up on anything. I also did that test on my 97 GMC Sierra in which I’m having no problems at all and the test was the same. Any advise
Sorry but you confused me on the fuse box process, lets say i checked the fuse both side right and left lead, and it does not light is that good or bad?
The test light must glow when touching both contacts of the fuse or the fuse is blown. If only one is lit, then you know that must be the contact closest to the battery before the break in the fuse. The contact point on the other side is now cut off from current because off the gap blown out in the fuse. If neither contact lights the tester then you are not receiving power at your fuse box or most likely you don't have your test light grounded properly (a common mistake).
For those who don’t understand, this is not about what you can do with the Test Light, “it’s how to use it” there’s a big difference. Unfortunately, you’re on your own to figure it out on that, or you could always ask somebody.
If the fuses are not near the battery, what can you use to ground. My fuse box is in the glove compartment, and I cannot find anything to ground to test the fuses.
Nice explanation with some good camera angles. It is worth noting that this is an incandescent bulb inside of the test light shown. If someone is probing a computer output that cannot source enough current, it can possibly damage the car's computer. Or if an airbag wire was probed, it could set off a airbag light, check engine light, or worse, could deploy the airbags. Use a test light with an LED or multi-meter if anyone has doubts!
Yes it can. You just need to know which prongs are connected to each other and which prongs when voltage is applied force the other prongs to become active. Then you can use the test light to see if the circuits are being completed when they should be and if not the relay is bad.
Anything less than the 12v it will work, but it will be dim instead of bright. For example, a lot of circuits such as the power to the injectors in some vehicles will show a dim light because they use only 5 volts.
Thats not true a lot of these test lights will light up at 3 or 4 volts all the way to 14. Thats why I think these style test lights are garbage. Used to own one and then went to a votage display test light all in one.
Hi there, Sorry to bother you, I invite you to use our test light for free sincerely , and I'd like to receive your suggestions and tell us the experience of used it.Can we?
@Damnit Bobby He was testing for ground. An alternator grounds through the bolts so the whole casing is a ground. It means the ground was good on the alternator only. A regular test light CAN NOT test to see if the alternator is working properly. For that you need a voltage tester.
So how is a 10 dollar test light checking the condition of a fuse and also testing to see if power is going through it? I'll wait. I own a 120 dollar test light that has a voltage display and will show when polarity is switched, I will never go back to just a regular test light. So many times the light will light up but its not the proper voltage and your screwing yourself in finding the problem.
@@2carpros So thats what you should say. Also how does one test to see if an alternator is working with a test light? Your confusing lots of people because you can't really test an alternator with just a test light. Not saying you don't know what your doing but your confusing a lot of people that are coming here for advice with words you choose. Only thing this video shows is how to use a test light and people are still confused. What all I have to say is why there is so many dislikes. At the same time if people don't know how to use one or how to figure out if an alternator is bad I guess there isnt much help you can give those types anyways.
75 dislikes vs 1.3k likes is actually a pretty good ratio here on RU-vid. This video is how to use a test light. Testlights are cheap and great tools to help sniff out electrical problems.
Not very good video bro... you show a fried plug....did you do a test to find that? But pretty obvious that it done working. You should do alot more tests. I think everyone knows how to test a fuse. Im having to find why my battery is draining can you use it for that? I also believe i have some broken wires in the steering column how about that? Why would my cig lighter fuse pop? How about that?
