How to locate an open circuit in a wiring harness 

Nearly 1:00am here in England and I'm still up watching this guy! Gotta be testament to his charisma though - no other channel would keep me awake this long.

Scanner Danner! You dont need to apologize for anything! You did a great job with the tools you had . You are a top notch mechanic with s great sense of humor. We need more like you!

Bought a short circuit, open circuit tester from Mac tools about `1980; consisted of a neatly shrink wrapped circuit breaker with alligator clip lead on one side and a spade terminal lead on the other. There was a small instrument panel sized round gauge with a needle and some coils inside no doubt, covered with plastic you could see through. You powered the circuit with the breaker/leads assembly and then passed that little gauge along the side of the trailer or truck body watching the instrument needle swing rapidly with a short or barely at all with an open. When you passed the short the needle returned to the starting point in the middle of the gauge. Passing the open had the same result. Worked as well as what you have but had no beep. I am certain it was Mac tools, before the split with Mac Allied Tool Company created Matco Tools. May still have that in one of my boxes out there in the shop, i am an old retired truck mechanic, for what that is worth. I appreciate you efforts with making these videos for folks like me that watch, learn and enjoy them very much.

Paul, thanks for taking me along on this diagnosis. I like hearing your diagnostic thought process and how you tackle electrical problems.

Hey Paul (and viewers), had a very proud moment I wanted to share. I myself have been a mechanic since 08’ but I am mainly an engine/transmission rebuilder and do very little electronic or diag related stuff. It’s been my total weak point my whole career. But since watching your videos last week I started experimented with a few small things here and there including fixing my own vehicle (wired up some LED running lights), and yesterday an I decided to tackle an old school Korean made hunk of junk that was a total mess. Had the weirdest of issues, turn signals were literally reversing themselves (right = left, left = right), but yet if you switched the indicator harnesses it would stay the same…if you turned on the running lights then those started blinking in sync with the turn signals…and only the high beams worked for the headlights. Normally I would have avoided this altogether, but this time I decided to tackle the job as a learning experience given it was a family’s vehicle. First success was the headlights, and it made it self known almost right away because the high beams died when I was testing it. Switch tested good, but resistance on the harness to the headlights was to the moon (forgot the value, but it was high), so there was the first clue. Ran a new ground, low and high beam wires and VIOLA! Lights work perfectly. Second issue was a bit harder and took me a good hour to find. Basically after using the techniques I watched you use with your test light many times in your videos, I was able to trace the fault to the ground pin on the gauge cluster itself. It was almost exactly like this video where there was one bad wire, except this one was broken right at the pin. So I repinned the ground and wouldn’t you know it, all the issues went away and even the fog lights came to life! Apparently this vehicle routed all the power from the signal relay through the gauge cluster first, and then sent the power to lights afterwards. So that was it, literally $1 of parts (one burnt out bulb), some electrical tape, and some wire…that’s it. Paul, thank you so much (if you’re reading this, which if not, no worries you’re busy). I just wanted to post for others to see as well because for whatever reason, the way you teach things makes sense to me. I’ve never been any good with tracing electrical faults, despite often reading books and watching other youtubers explaining things, despite being an engine mechanic. Now I have at least a somewhat fundamental understanding that I’m not completely clueless, and now have some confidence to branch out in repairing other faults as well, especially in this “new age” of electronics Thank you so much for the public videos (especially for people like me who live outside the U.S.), and God bless you mate. -A grateful subscriber

Damn, what a crappy year, first ETCG signs off, now RU-vid removes the carpet from Paul's feet!!! You two cats taught me more than anyone, I wish you the best Paul, keep the faith and do what you were BORN to do brother, help your fellow man.

I can’t believe you don’t have more subscribers. You are showing great troubleshooting techniques in real time which puts the onus of pressure on you while filming. You are an honest and brilliant tutor.

Excellent diagnosis . I'm impressed with your determination and patience and admire your continued searching for the open/short ! I really enjoy learning from you ! Thanks again for an excellent teaching video !

The spider reminded me of a auto clinic I attended years ago. The instructor said he had found a flea in a carburetor jet one time. He asked the students what would be the fix for a problem like this. One student suggested that putting a flea collar on the carb should fix the problem.

Just watched this video. When you troubleshoot in the real world with the trials and errors that you encounter is priceless. Thanks a million for sharing your knowledge. You make learning very enjoyable which it should be!

Man that was awesome too see how u found it. It helped me a lot I work on cars and electric is the hardest I’m 71years young and you taught me a lot. Thanks again. I’m from Australia thanks Dan

Nice find Scanner Danner, and to have the patience to diagnose while taping at the same time is incredible! Your channel Joes Auto Electric and South main Auto are my favorites

I can't thank you enough Mr. Danner, THANK YOU!

Thanks again for another amazing video! For once, I think I can help you. If you want to be able to "sniff" out any wiring issue like this, get yourself a Fluke Pro 3000 tone probe & generator. It will be the best $70 you spent in a long time! With this tone probe/generator, you can put a tone on any wire, even insulated wires by using the bed of nails in each of the leads on the generator. You don't have to hook up both ends, but if you're looking for a specific pair of cables, you can connect a generator lead to both sides of the pair on one end, then when you short them on the other end it will change the tone. This keeps you from having to make a second trip back to the generator to swap to the second wire you're after. It's powerful enough to find wires deeply hidden behind drywall, etc yet sensitive enough to be able to determine which specific wire you're after in a rats nest of wires. You adjust the sensitivity right there on the probe with an analog dial, and it has a headphone jack in case you don't want to disturb others or you need maximum sensitivity. A lot of people will say to get a cheaper unit, but I have found that similar to your experience they can be hit and miss. Fluke makes top of the line testing equipment and this is one of their cheapest tools so it's very much so worth the cost especially if you think you might use it more than a few times. I got mine originally to rewire my house and since getting it (and learning how to use it optimally), it has become one of my most treasured tools. I even use it for things it wasn't intended to be used for, like just putting the generator up against one side of a wall, then going to the other side to know where that spot is on the other wall.

I see ppl put all sorts of parts to fix a problem and never fix it. Helps to be very patient,smart, methodical

Almost at a 100k Mr Danner congratulations you have done so much for the auto technicians, thank you so much on my part

Watching your videos keeps me calm and I can really listen and learn . Even if I don't got your wonderful . Beeping box of buttons and clip switches with lights . I can still understand the protocol and procedures.

👍One of the best channels on RU-vid! Thanks for taking us along on another troubleshoot. Wish I had some of those mad skills!

Outstanding job and some great lessons on approaching a no start. No power at DLC, check powers. Sweet. Thanks Paul!

don't beat yourself up over it Paul, i'm 53 years old an i'm still learning new things every day, by watching peoples video,s like yours, Ivans & Eric Os .. anything i know about cars was through having to fix them myself, which at the time for me wasn't easy but thanks to a number of people who were willing to share their knowledge of cars with me i was able to do a lot of the work needed by myself... which took time...an a lot of mistakes were made, but i found that we learn by our mistakes or we never learn....when i came across yours an Ivans, & Eric Os videos on here after watching you guys working on cars ( oh an a shout out to Eric the car guy to ) .... i found watching you guys very interesting as to how you diagnosed each problem with the cars yous worked on an how you fix those problems, you yourself id give 5 star rating as to your teaching an training skills , if id only had teachers or trainers like you in school i would knuckled down worked harder, cause you have an excellent way of commuicating your thought processes... an i can tell your a down to earth guy an one who cares about his students an takes pride in his work....... cheers .....

Good one Danner! Great tool the es2000 friend of mine installed an engine 4.3 blazer vortec one version had two knock sensors and his replacement had one knock sensor so accidently he grounded the sensor wire thinking it needed a ground. the es2000 tracked the short right to his blue crimp eyelet ground. the tracker lit up at the pcm connectors like Christmas...five minute fix after it baffled him for a year

After watching your videos for the last month, I'm completely convinced that you can fix anything with just a test light... your awesome and this is cool as hell!!

You are a master, you tell your customers they are not paying for the 10 minutes but they are paying for your experience

Another great video, like the way you narrate all your videos, very informative the process you use and the presentations are so down to earth. Makes your videos so easy to follow.

Hey Paul I'm new to the channel but have been interested for years, just wanna say you're by far the most knowledgeable and straight forward with your explanations for Diagnosis and troubleshooting. Easy to understand when you have someone who can articulate the potential problems and solutions. Hats off to you sir and I will recommend this channel to anyone I can. Wealths of knowledge at no cost, thank you man!

As always Paul, I always learn something new, thanks.

This is a great video; diagnosing a simple problem that we all encounter. Thank you for sharing.

Great video my man (6 years later I see this). I just bought the ECT 3000 for my buddy and it works awesome. First time out the box my buddy found his short in his trailer wire harness on his '15 F-150 within about 30 minutes. Great video thanks for the sharing.

i watch your videos like the average american watching nightly tv shows - good stuff

Hey scanner you are going to be OK you've a tremendous impact in my life love your channel

I can thank you enough, your video reminded me of issue I had on a honda accord, intermittent transmisión problems some days not shifting from low gears. Some mechanics told me I need to get a new transmission. Started diagnosing myself and to discover that the transmission control board had some leaky capacitors . Replaced them and the car still running with no transmission problems.

Nice one, very good diagnostics ability. One thing I took of this video is the diagnostic thought pattern. Your thought pattern while carrying out an electrical diagnosis is very important. Thumbs up.....

Sorry for all the comments but me being an electrical diagnosing our services are seriously under valued a lot of times. But then pay the dealers a ton of money even when no repair was done. People think because I took 10 minutes to fix something I should get paid for 10 minutes. They don't realize how much research and studying is involved in dealing with cars. Especially now a days with cars having optical networks and all kinds of crazy wiring schematics..

00:42 in the morning in UK...might go to slee..... damnit. new SD video. *puts kettle on* :)

You are a great troubleshooter, and narrator. Thanks ScannerDanner for showing us the power of a single wire. Also, your video always will be useful for someone.

Great video !! Always have great appreciation for old school techniques the scanner tools are helpful but yup gotta take the long hrs & practical use in order to master the process...scanner Danner did a great improv using basics & his 18 years plus experience is always in his back pocket....Videos are alot of fun to watch maybe other viewers share this thought where it kinda feels like you're "there"I get the notion the video was pre empted but extremely practical and a sense of accomplishment for the viewer. My own diagnostic situations found me using an am radio 📻 on an unused frequency after all the tools themselves are composed of the transistor & receiver same as wifi 📶Take care all !!

the "check previous mechanics work" is lit brightly :))

Every modern wire sniffer I've seen has that useless "auto-off" feature. I like that adjustable sensitivity, though! It's rare that these things actually make themselves useful, but I've had very, very good luck with the telecom sniffer I have from the 80s. One sensitivity, one on-off switch on the sender, one "pick-up" button on the receiver. Great video, Paul! Saving another customer from a nightmare. :D

Man this video was immensely satisfying. It was great to see you troubleshoot this issue. Great work!

you know your stuff. I am completely convinced I can fix my problem wire harness watching your videos. keep up the great work you do.

The tone generators we use every day in telecom work are a real lifesaver, you can isolate one wire out of a thousand 1/2 mile away just powered by a 9 volt battery.You can hold the probe tip between you fingers in one hand and run your fingers of the other hand down a terminal block and pick up the signal right through your body. These are designed for maximum power and sensitivity because of the distances involved. They will sometimes inject the trace signal into every conductor in multi-pair cable by induction or in the case of a car, every wire in the harness. It seems the tool SD is using is heavily desensitized because of the close quarters and short distance of automotive wiring.

Mr. Danner. Thank you so much for this video and your other videos. Wish I worked for somebody like you. Tons of awesome info, thank you very much for posting all these videos. I hope you get paid for this because the info that you post is Invaluable!! Thank you again sir. Michael McNabb .. Subscribed and re posted .. thank you sir.

Awesome work, fella - that's exactly the sort of hard-to-find break that does my head in! 🙌🏻 👌🏻

I enjoyed this video. I did a similar thing with my car (replaced a lot of parts when it was a short in the circuit). The tool wasn't a turnoff at all since I personally learned something along with you. GREAT JOB!

Best diagnosis finding “is that spider alive... no, it’s not”

Pull the 30am fuse out that will isolate that cable from the rest of the battery circuit some times the signal will be on other circuits that mite feed off the up stream side of that 30 amp fuse and can get you confused was court out like that one and chased my tail for a day. Nice one mr danner big thumbs up 👍

What an excellent fix Two Thumbs UP for Mr. Danner.

Between you and SMA, I've learned a ton about finding broken wiring on vehicles. Always look for collision damage, bends in looms & previously molested wiring. XLn't video Sir, thank you!

Love that zoom effect and the key is in your pocket.

I used to use a simple two wire flasher and a compass . When the needle starts to stay continuously there is your open

Have the same problem with my nissan sentra se-r. Very helpful video. Keep up the good informational videos

I have learned more watching your videos than any other youtuber. I recently had my A/C go out, so I stumbled upon your A/C videos in search of a fix. After using your diagnosing techniques from the interior all the way to the A/C clutch, I discovered I had not fully seated the A/C clutch connector when I changed my radiator a couple months ago. Talk about a welcome "click" when I pushed the connector together last night! (Actually the best "click" was the sound of the A/C clutch engaging when I jumpered the relay 🙂). Anyhow, even though my A/C problem was "best case" scenario, I still find myself watching your videos purely for the education. Thank you!

I had that same exact issue on several cop cars back when I worked at the city. Took me longer to diagnose though. Great videos man!

Mr. Danner, I love every video that you do. And this has been one of the funniest ones I've seen. The fast forward of you pushing the ca in the garage and the tool giving you problems. Sorry for laughing, but this video brightened my day.

U always give hope to us younger n hungry never earned a certificate people...one day...maybe one day .well be like you ...thank you for your knowledge and patience... scanner Danner premium is on my to do list this year or the next .mark my words

Is this a police intercept engine? Man, i have a strong desire to be great at diagnosing. Its the best feeling to look at a car that many mechanics (part changers) have been arragantly dismissive of anything i have to say, and fix it, when they only threw parts at it. It takes brains and not testosterone to be costly effective, and not waist the owners money. It keeps me going. Thank you for being there for me. Even though you didn't know you were! I would love to take all your classes.

Keep the good work up Paul!

CONGRATULATIONS ON REACHING 100,000 SUBSCRIBERS. THANKS FOR SPREADING YOUR KNOWLEDGE AND HELPING US OUT!!!

I so enjoy yours and south main auto videos, you both do great work.

This was just great. With the fuel pump problem I'm having, this was right in the zone. Your the guy that goes with what's really going on. This was trouble shooting with all the moles and warts. It is the real thing. I have a harbor freight cen-tech short finder. You gotta use it right. I had to learn the in's and outs of how it works. You have to improvise jumpers. You did a great video! Thankyou!!!

Ready, aim, fire the parts cannon! Boom, boom, boom, boom, boom, boom!

Good to know I'm not the only one who thinks OTC uses a boot on the test light clamp that is way too stiff. I don't know what kind of gorilla engineered that thing but it takes both hands to open the clamp with that boot there. I pull the boot back just like that, myself. Good video.

I’ve found to have issues in harness/wires more often then actually a failed components. I’ve been working on ag equipment for 15 now, un wanted resistance in circuits eventually turns into the “green crusties” eating through the wire. Good stuff man.

Excellent tutorial on wiring harness. Although its time consuming its well worth it for the fixed end result.

The short/open Circuit finder is a great tool but it takes a bit to learn how to use it. There is a video here on youtube that explains how to use it. The tool shows a grounded circuit because the wire being tested is connected to another component on the splice. Since there was no power at the DLC It suggest the break was before the splice. I think the right way to test it would've been by removing the fuse and feeding the signal thru the fuse box that way the circuit gets isolated on one side by removing the fuse and at the other by the break in the wire

I have the older version of that tool and used it for yrs and have found many broke wires with it

I’m a mobile mechanic in Tulsa Oklahoma I’ve always wanted to be as good at electrical as I am on rebuilding power trains and other grunt style work, I was stubborn and taught myself to a point where I could find shorts most of the time and make repairs but it’s not always so easy so with the help of scanner danner and my newer electrical diag tools and new knowledge that expands the more I study and watch this channel I’ve been able to take on jobs that most guys turn away cause there scared of electrical.

I followed my best friend like a shadow whenever he worked on cars. I learned a lot about cars from him but I never learned how to chase a short. Thanks Scanner Danner.

Paul, I just watched your video about the premium channel. I hope everyone feels the same as me, I will follow you no matter where you host your video's at. God bless you sir...

You sure know how to tell a story with your editing. Picture in picture, zoom, sound, everything. You videos are always easy to follow along. Great find. I'm getting to this one late and we know what happened to the paid channel. It still sucks.

ETC3000 was a life saver man. Good Job 👍

Thanks for the videos I enjoy them! ! I have a Harbor Freight wire tester some what like what you have but easier to use I think. The Harbor Freight tester can be used on phone lines house wiring, cables. And then for automotive wiring as well. One thing I like about the Harbor Freight tester is it has two 9 volt batteries that you can use anywhere you don't need an automotive battery. If I was back working on cars for a living I would probably buy one like yours, I love Power Probe tools. I have been disabled since the early 90s, so something from Harbor Freight are fine.

Did you ever do a video on that ECT3000 Circuit Tracer

27:55 that’s what she said. Lol . Great vid per usual. That line never gets old.

This video help me me fix my crown Vic. Runs great. Thanks scanner danner

The ECT 2000 is the best tool I've ever found for finding shorts and opens, if the only automotive tool which will do the job. That being said, the use of the tool requires intimate knowledge of the tool and the circuit it is being used on. First issue of understanding is to realize it has two mode of detection, electric field (oscillating voltage on an open wire) and magnetic field from current flow, and it tells you which mode it is using, even to the extent the direction of the current (direction of the detector tip is important). Most detectors use only the electric field which is usually present over the entire harness of the car due to the vast interconnections, isolation of the wire (disconnect it at the source, apply the signal, then trace) is required to follow the signal. Tracing current flow is much more straight forward because the current is limited to only it's path, but keep in mind the path does include the power feed lines to the signal generator. I believe the current mode kicks in at about 100mA. I do not work for Power Probe so the description above is only from my use and experience. I agree they should give more technical details of it's operation.

Personally, I perfer a multimeter to check my spiders for life. Good to know a test light would work as well tho.

how can you put an alternator and a fan in there for a no start condition ?

This is the best video so far (barring Stephens lol) I have watched and enjoyed along with Simply Diagnostic. I'm not familiar with most technical terms but the practical aspect is very good. Defo a channel to keep an eye on. Excellent video and work.

Very useful and informative. Thumbs up for Paul. Keep it up!

Reading instruction on a tool feels like a chore. Playing with a tool first feels like a new toy.

Can I be honest in saying that an oem diagram that shows actual connectors involved would have cut this diagnostic time to a quarter of the time? I don't mean it offensive as I hope you know, but this is a prime example of why Mitchell sucks the big one. One quick check at c102 and one at c104 would have given you a very short area to work with. Heat and vibration to find the rest . Great fix as always though! Be well and god bless

Great job. Now everyone can see why you can’t put a price on electrical problems as well as why it could be an expensive. Thanks for the video.

Excellent chase-down, thanks for the video.

owner really needs to install a fan shroud

I love live filming like this. No need to know everything, more fun to watch the process we all go through as we figure cars out.

Love that tool ! Power Probe hit a home run with that thingy. They have a amazing videos at their website. Not a sponsor. But has saved people money, and made me look like a wizard ! My Gpa once told me," It'a a poor musician that blames his instrument. Nobody can play a symphony on a harmonica."

I try to watch all of Paul videos. They saved me a lot of money. I remember what I was told dont be a part changer ..i been trying to get my cruise control to work properly on my old truck. One thing i seen on my vehicles and at work on equipment is well it was working great until it was not ... i finally got the manual out and started checking inputs out puts or whatever is called . Volts and knowing that a load can change that if there is corruption ect . FINALLY i found a lack of voltage at a pin on the pcm .. Broken wire in the harness i guess . I ran another wire and fixed the problem. Then the cruise control would work but drop out . Bad brake switch damn . Sometimes its more than one problem....i always refer to Mr Paul Danner channel as where to get trained and helpful tips . Thanks again for what you do sir

New subscriber. Great information presented in a painless, learnable way. I have experienced your frustration with a toner tool and LMAO. I am pretty sure I said the same thing too. This is bull**** . The rule of thumb for that is : It will only happen in an attic or under a car. It was fun to watch your proficiency using the tool grow as the video progressed. Your honesty is palpable and appreciated. I believe sir you found your calling! I also think you will find a good toner something that you turn to frequently.

Great video. I like these wire tracing videos probably because I don't have much experience doing it. Maybe this will help me fix my problem in my van. Lights only work when the key is on and started right before I changed the radiator. In changing the radiator I found evidence that the car was in an accident. Trans cooler bracket broken so I guess the body shop figured no one would see it sandwiched in between the rad and condenser. Oh and the rad went bad because of this cause the cooler was loose and rubbed a hole into the radiator. Thanks for the lesson.

Thank you for showing liquid tape, I’ve been down that road before. Used electrical tape because I knew that I couldn’t use heat shrink tubing.

Great experience. Thanks for sharing and I hope you find another way to proceed. I'll be watching whatever direction you go.

had similar problems with test kit that dosent work in all senarious the surrounding wires like you had sometimes due to the capacitance effect can induce the signal into the other wires especially if they have become twisted in the loom and then the whole thing gets very misleading with false signals in associated wires bear that in mind when using your test kit but the end result you came through it and fixed it every jobs a fresh learning curve good video shows the difficulty of signal tracing in multiwire looms

I must admit when you read off the vehicle specs I was channeling Eric O. with "there's your problem"! LOL. Great video though. I remember doing stuff like this on commo systems in the military (APCs, tanks, etc.). Nothing like a turret ring on an M-60 tank!

Wow! That tool is a life saver. Maybe it's time to upgrade to the latest and the greatest! Good job!

yup- having the right tool helps like you said you got lucky but if you did not find the yellow and black wire problem to begin with you may have never fixed it so great job, buddy

going through the same thing with my hybrid! thank you so much for this video🎉 i truly believe it will help me fix this short/ground after wasting thousands lol. changed 12v battery, Hybrid starter generator, drive belt, safety fuse and HPCU on my 2013 optima. dealer diagnoses HSG originally so i replaced that, no difference. i’ve been to multiple shops and i’m done wasting money on big parts when it’s obviously clear they work by the KDS scan tool!

the toner showing shorted is no issue its just feedback from anything else that's grounded in that circuit. That's a great tool especially when looking for an interior short because there is no need to pull rugs or trim panels. makes finding electrical critters essentially easy to diagnose

Well done Scanner,enjoyed that video you certainly know your job.

great diagnostic dan, very thorough and concise diagnostic technique.looking forward to update sometime on the continuity tool.many thanks..