I like that you actually do your diagnostics before you start throwing pars at it

I thought it was funny how your meter said “ouch” right before you told us how much that fuse costs. Lol

The sharp point on the tester lead (small point of contact surface trying to carry the needed current to promote charging), was the reason for the tool heating up I’m thinking. I’m a retired mechanic, (retired due to medical reasons and disabled), and am subscribed to your channel as I find you have a very good characteristic and very honest in your videos which is very refreshing indeed.

Some mechanics are not actual mechanics anymore they are parts replacers and do not know how to diagnose problems. Im glad to see you actually go through the effort to see what is actually wrong with cars.

I believe with the way you hooked up your temp. fuse to wire #3 post, it is actually in series with the #3 fuse. Should have gone to either wire #1 post or the lower post.

I never knew that was fused like that-what a great video. Can’t imagine how bad the EV’s will be to work on. I’ll be sticking to the old stuff. Thanks Kenny.

My wife's 2013 Infiniti EX37 (45k miles) , the small suv, quit charging. I made an appointment with the dealer since it has the smart charging system. I charged the battery just before going to the dealer and I ran the engine at the same time and the alternator started charging again. I can only surmise that charging the battery with the engine running woke up the computer. The car's computer had a brain fart!!! That was about a year ago and it still works fine.

Outstanding mechanic.... Wish there were more like you sir.. where I live we have no mechanics only town families who think they are... I'm no mechanic but have watched videos like this and yours helped me fix they asked what I did to fix , I said I got educated... They of course got mad and don't talk to me... Three vehicles setting here no one can help me fix them again I'm no mechanic so it takes me longer but sometimes what I do fix again from videos as this , is how I catch there lies .. thanks and God bless you brother and this is from Master plumber not Master mechanic 😂😂😂 really god bless

I find your videos educational and fascinating. The way you work through the problems you’re facing is inspirational. I told my wife that any kid who works in your shop is blessed to have such an experienced technician on site. As always great job.

It is great to see a mechanic who can dia.

As soon as you touched the test light to the fuse location the engine changed tones and I knew you were going to get the problem SOLVED 🔧👍

Great job troubleshooting, electrical issues can be a bear to fix sometimes. back in the days when I worked on cars there use to be a easy way to put the alternators into "full field" to see if it was charging, if so the alternator is not the problem. I remember we had a car go thru the shop several times not charging until it got to me. I asked the techs what they did and I scratched my head for a few minutes and before I started to dive into it this car had a few dashboard lights that were out (just the lights to see gauges at night not indicator lights) so I pulled the dash and the circuit board had a burnt spot that fed power to the alternator lamp once I jumped it the car started charging again, I just got lucky!

I love that you're smart enough to make sure the alternator is getting power to the "excitor wire" that you check the fuses

It's a good thing that wasn't shorted.. jumping the alternator to that #3 wire basically double fused it. Limiting the amperage to the battery and the rest of the fuse box to what ever the 3rd wire fuse was (assuming because of the wire size 50-80 amps) but creating a new 150+ amperage possibility to go to the #3 wire. Using the fusible link wire was a good idea to test but always go back to the main buss bar (wire #1 or the fuse box nut)..

I always keep a tube of Dielectric grease handy when working on electrical apparatus, Whether wiring connections or ignition, bulbs and sockets (DON'T GET SLOPPY ON THE SOCKETS) Fuses, any connection that doesn't move, including battery cables/terminals! I really hate re-curing problems , which are usually caused by corrosion. Thanks for the videos, just subscribed!

Perfect opportunity to demonstrate a voltage drop test.

Wow, the same thing happened to my friend and I when we diagnosed a car with a "bad" alternator but then found out that a big fuse had blown and someone before us soldered it together. We put a new alternator, but it was doing the same thing until we figured it out. Had to go to the Honda dealership to buy the fuse, installed it and everything worked as it should.

I like your videos. Your very honest and I can see you always do your best. I'm a slow learner but I did pick up what you were teaching. The vw got towed to your shop and the thought was it had a bad alternator. Turns out you diagnosed it had a bad fuse. When you get the fuse from the auto parts store you can replace it and see if all is good. Bravo!

Well done Kenny!! Great job of using plain 'ol common sense and logic in tracing the electrical to a defective source. great job!

What refreshing change to see an honest and decent guy doing work on people's vehicles with integrity and care. Unfortunately here in Englandistan the respective governments have strangled the self employed auto shops out of business, for one sole reason, they hated any every and all businesses taking cash because they were afraid the tax man didn't get his cut!

You're the difference between a genuine mechanic and a backyard one like me! I would have never thought of that! Thanks for your tips!

I would recommend getting a clamp on current meter, you can clamp them on any wire and read the current going through. Very handy, a lot more accurate than looking for smoke and/or measuring the size of blister you get from a 10 AWG wire.

I'm currently driving my 4th passat, it's good to know about that weird hidden fuse. Nice diagnostics.

Really enjoying your videos thank you Kenny

you can also use a couple of circuit breakers as a temp jumper as long as you dont turn on any lights etc as many modern cars have variable output alternators so only put out the current they need and not 90 Amps all the time. nice video. i have also had vw fuse boxes that just melt as they seem to like using what i call bent metal links inside rather than wire, i have changed many of those over the years for odd electrical problems.

Kenny, I think your theory on the car being jumped incorrectly holds waters , if the problem was a pattern failure, ( bad alternator ) you would see it in service information right away like IDentifix / and Alldata having a 200 amp fuse burn open would most likely be something like the positive battery cable rubbed through short to ground. I have seen on fords the car jumped backwards takes out the alt and the PCM .

In the late 70's, early 80's a friend had a gm car that was not charging, even after an alternator and a battery replacement. I checked by bypassing the regulator and it charged. Tested the tickler wire and nothing. Checked the fuse, which was good. Then pulled the alt light bulb out, which was blown. Replaced bulb and fixed the problem. A 2 dollar bulb cost all those unnecessary parts to be replaced due to incomplete diagnosis.

This is a GREAT video. Very informative. I’m subscribing so I can watch your other videos. Another issue about how such a large fuse could get over loaded is if that car was used to jump start another vehicle while it was running. I learned several years ago that when jumping a dead vehicle the good power vehicle should be turned off. If the non starting vehicle won’t start when jumped start the good vehicle and let it’s alternator charge the dead vehicle for 10 or 20 minutes before turning it OFF again before attempting to restart the dead vehicle. It might take a little longer but the alternative is the dead vehicle starts and drives away and a day or 2 later your vehicle is not charging because the voltage regulator or in this case the power bank is fried. Something else that caught my attention was the coloration of the overloaded circuit terminal. It looks to me anyway like it was running hot for a while before it finally “popped”, indicating a different issue. Thank You for sharing your knowledge. It’s inspirational. Joe

I like the 'ouch' on the multimeter.

Good info loved it I had a car a couple years ago same thing happened I ran a jumper but had no idea that was a fuse until I watched this I subscribed to you didn't show alot of unecessary BS

This does seem to be a common theme for years. I had a 02 Chevy Silverado that went to 3 different mechanics that couldn't diagnose a p0300. Only code it would throw. Turned out to be the crank sensor. Cost the poor guy thousands in diagnostics before I got ahold of it.

I tried starting my ford f800 with a 7.8 diesel with low batteries. you are correct it's not a good idea to keep cranking the engine. When I pulled the battery cover to connect the charger one of the lead terminals melted off. Lesson learned.

I've had several different Vows roll into my garage with charging issues. In all but 1 I discovered the connector soldered at the fused battery box is bad. Idk if it's to much solder or what but with each one I cut the original end off and solder on a new copper end with minimal solder and its 100% good again.

Thanks for the videos Kenny!

Well the fix does allow charging, but that #3 circuit lost protection and you are putting all the alternator current through the smaller fuse. Better fix is fussible link between 1 and 2. #3 maybe power to starter or computer power

Funny story, Customer brings in jeep, not charging. He just put on an alternator. Parts store tested alternator said its bad. Still not charging. I did a basic diagnostic, seems this jeep has a maxi fuse for power feed. Checked it, yep its blown. Replace the fuse and it was good. Dude didn't disconnect battery and shorted ALT PWR. during repair.

Perfect as always, thanks for the education kenny

Thanks for the info. I’ve had as simple as a vacuum hose from brake master to intake crimp and mechanics say that would cut my brakes and not be shutting down 3-1/2 cylinders. Took my truck and went to store. $7 hose and I pulled back to shop and my 5.7 was roaring again.

...as usual a great bunch of info for us diy'ers.

I worked briefly on an starter and alternators shop and a guy came to buy spares for a magnetic marelli alternator, one by one bought everything but the case and bolts and told us that the alternator was not working, we put the complete unit on our alternator tester and worked fine, all parts were new so was no surprise, then he asked to bring the car so our mechanic can take a look at it, was an Alfa Romeo with a V10 engine the battery was not charging and as you can imagine turning on any accesories like the car stereo or ac shuts the motor down. The problem was very simple, the motor have a slow idle speed so the alternator just cannot charge the battery nor mantain enough current to make the car run all accesories, just adjusted the timing and was done.

Your amazing diagnosis skill saved the customer. Another reason NOT buying a VW group product due to idiotic design all over the place !

I like how thorough you are. Thanks

You put your fuselink on terminal 3 that is after the smaller fuse. The fuselink should be betveen terminal 1 and 2 !

If it was my vehicle, I'd install a 200A Mega Fuse from Digikey for $7.47. Wire the fuse between terminal 1 & 2 for proper connection with the OEM fuse.

Fantastic troubleshooting. Kudos brother.

A True Mechanic! Great Video!

Place i work at is a full service auto shop plus a body shop. We also have wrecker service and a auto salvage yard. I get to fix stuff the body shop messes up all the time. Also get to do accident related repairs all the time.

Cool. I've never seen a fusible link/block like that.

Kenny we need to go fully back to old chevys, dodges, fords of the 50's

Great video! Once you knew it was bad you can pop the plastic cover off and verify the blown fuse link too.

Another good job done

A couple of points in my day in 1980s the only thing that generated or consumed over 150 amps was the starter motor. Even alternators would generate about 75 amps. I was thought never to run the starter more than 12 seconds. That was in the days when the comm was made of copper.. Other thing of note, when i was tracing elec faults i always fed the engine via a 10 amp fuse. or single strand of copper wire between positive battery and its terminal. It prevented accidental short circuit. With modern cars, a car with a flat battery being jump started from another car, the doner car should e started and allowed to charge flat battery for a 10 minutes. This prevents a surge of electricity when flat battery car starts and starts charging at max rate and before jump leads are disconnected. Aslo in my day in Europe, some cars had a positive earth.

Thank you for the insightful diagnosis. They are very enlightening and interesting. Keep filming.

I hooked a battery backwards on a Jetta of the same year because the ground wire looked red but it was really brown. That same fuse blew. I verified it the same way Kenny did. Took my butt to the junkyard and got another one.

i'm guessing you were a mechanic long before all the computer and electronics of today. pretty obvious you think beyond what most scanners tell you. being older than dirt i enjoy watching you use common sense plus todays technology. and for some reason you look very familiar, maybe a tv series?

Interesting, so many hidden fuses and connections, good find

That is a dirty high resistance connection and that produces a voltage drop across the connection. That produces an IXR power drop to be produced there (which is HEAT!). That is the heat that warms your test light tip. If a high current was flowing thru the tip, the test light bulb would be FRIED. Disassemble that connection completely, scrub all mating surfaces with fine scotchbrite pad, and reassemble with silicone grease on ALL mating surfaces, IMHO. BTW, when you pressed the tester tip onto the connector you improved the connection momentarily.

You should have more subscribers. You are very good mechanical,and narratives.Keep making vids Kenny😊

Good find.

Thank you. Clear and understandable info.

I bought a bronco where it's owner had swapped engines. He said it was wired wrong and discharged the battery instead of charging. He had a couple wires switched up. A TRIP TO THE LIBRARY...is all it needed

Maybe I'm wrong, but testing the voltage when running I turn everything on to create a need for the alternator load, then look for 14 volts or better. The alternator is then required to work at it's peak so I know what that peak is.

Low volts=high amps, which blows protection circuits.

I had something similar happen to me years ago. I had a 1993 Dodge D350 with the 5.9 Cummins and it stopped charging. Come to find out it was a fusible link that had melted

Good one kenny😊

hey kenny ive seen those megas open for no reason before heat cycles then fatigue

lol. I just had this kind of thing happen with a Jeep, actually. whoever had it last had the wrong size battery in it (a 54?), and when I bought the PROPER size, the tech putting it in faced it the exact same direction as the wrong battery...AKA backwards. three alternators and a sale later, i found out...a fusable link had popped in the alternator wiring. didn't even know they were still USING fusible links.

Yeah. Hooking up the battery correctly will also not mess up the ECM. Hook positive clamp first then ground. Reverse procedure when disconnecting. 😎

Good find

Diagnosing charging and starting issues has really become complicated. Many newer cars will show a significant current draw for a half hour or more after shutdown, before they actually go to sleep. And GM for instance uses Electric Power Management to vary the alternator output. It uses 6 different charging modes and can vary from one to another at any time. Battery charging voltage can read anywhere from 12.5v to 15.5v. All considered normal.

ive replaced many of those some of them will get so hot they can cause the fuse box to catch fire or just completely melt it down also id recommend an alternator even though it appears to be charging good

I'm a bit confused. Shouldn't the Fused Link test jumper go to the stud on the Fuse Box and the stud on the buss bar? I looked to me that the three studs labeled with a marker 1, 2, & 3 were part of the long buss and the other stud is the one that goes through the blown fuse.

I wouldn't put anything past someone. I've heard of very intelligent people putting 120V AC to the battery thinking it will allow then to start a car. Anything is possible and in this case, someone probably either reversed jumped it or was wrenching on something positive leading to the alternator and the other end of the wrench touch metal causing it to short, popping the fuse. I once dropped a wrench while adjusting a hood and it landed just right on the battery + and popped the 175A main mega fuse. Luckily, the fuse did its job and nothing else was damaged.

What would be wrong w a good junkyard fuse to replace the 200 AMP MAIN? New are kinda overpriced as you said.

The low battery and high charge current was probably pretty good with the test light tip.

Very interesting indeed! Great diagnostics ... ;)

That tree out side your shop looks close to your building

You remind me of a co-worker that I had. He had the best "street" smarts of any mechanic I ever worked with. FYI - Fusible link wire is no different than regular wire of the same gauge. The insulation is a high temp, so that the the wire can burn through, but be contained by the insulation. Also, fusible link is usually 2-3 gauges smaller than the circuit it protects, plus the length matters, too. Do you have access to schematics? I enjoy your videos!!

Good one, thanks

The 150amp ”fuse wire” may not last forever, but least as long it remains in series with the 80amp fuse…..

I saw an old Hyundai that had stalling issues. The frigging plastic clip for the prop rod was broken. Lady would hit a pothole, prop rod would ground the battery. Then she'd raise the hood, use the prop rod, and it would start right up. Then it would bounce out of the broken clip, and it would stall. The old timer that could change a U joint in 45 seconds with only a jackstand and a 3 lb hammer diagnosed it in like 3 seconds.

I’ve also seen where someone welded on the chassis with only one terminal disconnected instead of the whole battery leaving a path for destruction 😂

That is the weirdest setup I've seen and it makes me really glad I don't buy VW.

you connected the jumper fuse to the other fuse instead of to B+. Will work I guess for low current draw.

Did you check the other side for a short to ground? You jumped the alternator side but what about the side that is still in the fuse box? Run you're ohm meter to ground and touch on that stud with that weird fuse looking thing disconnected. I would but you probably did that good video and thanks.

Back to Ohm's Law. Low voltage requires high amperage to start.

Had that happen on a Nissan I had years ago, Dealer said the Alternator was bad replaced it did not solve the problem then replaced the Battery, not the problem, took it to a Starter and Generator place, a few hours later the car was fixed it was a short in a wire.

But why did the 200 amp fuse blow?😊

Nicely done as always

well done, it is a true tracing !!!

thanks a bunch

Had 2 self proclaimed electrical expert shops misdiagnosed my parasitic drain.

Aren't fuses supposed to be cheap components which fail to protect expensive components? Having expensive fuses protecting expensive components is very poor engineering, a good reason to avoid that brand of vehicle IMHO. Great video.

Hey Kenny, I wish your shop was closer to Connecticut cuz I have a 2001 Ford Expedition and it needs intake manifold gaskets and I DO NOT want to tackle that.😂

pretty sure left to right is battery, alternator with the one behind it powering the fuse block , then the starter lead on the right. so you jumped it with the fuse link between the alt and starter. bad part with that is then the starter fuse is taking amps the alt fuse was supposed to.

I had the exact same thing on my 2.5 golf. Except I figured it out after I threw a alternator at it..😂

Great video

You can't train this kind of troubleshooting. I've told many, many people with vehicles of a certain age, to take it to a mechanic with grey hair. I remember a Trooper II with fuel issues that turned out to be a partially blown fusible link. Someone also dumped too much methyl drygas in the tank and it wrecked the injectors. I have I idea how the link was related but it wouldn't run, then it ran like crap until I dropped in the injectors. Ran like a top after that, until the owner rolled it.

Not to say anything bad but hadn't you looked at your shop door I still think you're pretty good mechanic That's why I'll watch

fuse or diode ? nice job