I’ve worked in 2 different shops in 5 years and yes they do actually diagnose here

Yeah, they kind of do. Perhaps they'd miss it on the first pass if the initial complaint was AC inop. In that case the mechanic would replace the fuse and look for some obvious problem like a chaffed harness, run for a bit and return to customer. But if the complaint was AC fuse keeps blowing it would diagnosed more throughly.

You have a negative world view.

Valuable information! Thank you!

A 12 volt beeper is also handy to use . ( Class 8 truck low air pressure warning beeper )

This technique is as old as the hills, and I thank you for mentioning it. You don’t need $8 billion worth of tools to pinpoint a short.

Every job is easier with the "right tools"!

@@shannonharris that’s right.

What model megaohm meter do you have? I have a fluke for hybrid/ev stuff but it puts out 500 to 1000 volts.

@@Issues198I have the 1587. It’s very similar to yours but has an adjustable range from 50V to 1000V. I use it to check windings for industrial compressors and generators. It’s very versatile.

You can't look at the number of amps, but the ratio. Imagine a 30amp breaker allowed 55% more amps...

Resistance was rising over time , hence the higher current. The system was working correctly but would blow the fuse so no need to monitor voltage. The system was capable of delivering more current than the circuit was designed for so a voltage drop test was not necessary since there was no lack of current flow. It is all in Ohm's law.

Yes. If you look at the time vs. current curves of ATO fuses, for example, it will take about a minute for a 10A fuse to blow with 15A flowing through it.

Many times fuses may run their lifetime duty cycles out , constant heating and cooling of the fuse . Fuses are placed into pressure sensitive terminals , heavily poking them with a test light spreading them permanently open .

@@vicpetrishak7705 Thank you. Makes great sense.

If you have low charge , you will hear the a/c clutch cycle on/off frequently.

With swash plate variable compressors they no longer cycle unless hi pressure kick out.

I just buy resetting circuit breakers from the Pico electronics catalog and use the fuse adapters and some terminals and wires. A less expensive option that's worked great

A regular fused loop with amp clamp would work if you have an endless supply of fuses. You could also buy regular circuit breakers. A Fuse Buddy would be a poor man's all in one.

These videos are not meant to teach DIY guys how to fix vehicles. They are to teach how a knowledgeable technician in a professional setting with proper equipment can properly test and accurately diagnose a problem. No professional shop is going to lose money by spending 10 times as long to do all the testing with dollar store equipment just so a DIY guy feels better about it and learns something. If you want to work like a professional, you gotta spend the money on equipment. There are cheap scopes out there.

@@thatguy7369you totally wrong bud…professionals with expensive equipment shouldn’t watch videos to fix something if does isn’t any professional them any DIY guy

@@bikerboy6985 brother, you have no idea. You are the unfortunate victim of the Dunning-Kruger effect. You think you know what you are talking about because you know so little that you don't realize you don't know anything. Only about 10% or so of mechanics even have the slightest idea how to use a scope in the first place, nevermind be proficient at it with testing complex electrical issues. You can walk into any shop in America, and if the shop has 10 mechanics, they only have one, *maybe* 2 good mechanics, 1 or 2 others who aren't all that good, but also aren't terrible, and the rest of them shouldn't even be touching cars in the first place. And those 2 good techs probably don't know how to use a scope or how to properly test and diag ose electrical or drivability issues. This is why shops and mechanics have such terrible reputations, because they are actually terrible at fixing vehicles. There are literally mobile diagnostic mechanics in most medium and large cities who don't work on a single regular customers car. Instead, their entire business revolves around traveling from shop to shop, all day, every day, diagnosing electrical and drivability issues for those shops because those shops literally don't have a single mechanic in the building who can accurately diagnose most problems. They are hired and paid by the shop, and the customer usually has no idea the shop had to outsource the work to another business because they weren't capable of figuring it out. No, my friend, this video is not for you and the backyard Billy's of the world. This video is to teach other professional automotive technicians a reliable way to test with the proper equipment, and to show potential customers that this shop knows what they are doing and why they charge for testing and diagnosis. For you, it is only entertainment.

@@thatguy7369that little I know it’s more than yours…I didn’t claim im professional like you knowing everything and understanding everything and teaching yourself from youtube like big professional nothing wrong to have that kine off complex you are not the only professional does that “ i saw on KZfaq”…how i said I’m trying to learn from this channel some videos are helpful some doesn’t

​@@bikerboy6985 brother, you need to learn English first. Also, I haven't claimed to know everything, you need to learn reading comprehension as well. You are once again a victim of the Dunning Kruger effect, you know so little about what you speak that you make assumptions and accusations as if you actually know. But you can't even comprehend how little you know.

You're assuming at that point. What happens when you replace the clutch and the car comes back a week later with a blown fuse? Is it a part of the harness you didn't catch? Maybe the compressor itself drags when hot? We professional technicians always want to confirm the actual problem. You don't need all the equipment shown but the test is still the same.

It’s just a really fast graphing multimeter and instead of just looking at a digital number you are looking at a line graph that represents that voltage over a length of time. Your time base is just the length of the time window you want to see. The trigger is just to stabilize the waveform so you can make it focus on a certain event and put it on the screen where you want it consistently. Think of the trigger like a timing light. The waveform is like the crankshaft moving so fast you can’t process it. Putting the trigger on the screen is like dialing in the advance on a timing light. You’re telling it where you want that waveform to appear so every time the voltage crosses that threshold it’s happening right where you put that trigger. The time base is like a horizontal zoom. A larger time base like 1 second per division will be like your zoomed out seeing multiple events across the screen. Lowering the time base is like your zooming in where there’s less events on the screen but you can see them in more detail. Best thing you can do is grab the scope when you have a minute or two and hook up to some cam/crank sensors, fuel injectors, and coils. Play with the time bases, voltage, and trigger settings and it will start to come together. Once it does you’ll wonder how you ever got by without it.

PICO has A-Z on there website.