Motor Age How2 #3: Using AC Coupling On Your Scope

Hooray! We finally get to capture a REAL voltage trace on our scope! And on top of that, we'll learn how to use AC coupling to eliminate the DC component to actually test the alternator's diode assembly.

Be sure and SUBSCRIBE to our channel so you'll be the first to know when new information is available!

@@@ FOLLOW US ON @@@

VISIT OUR WEBSITE!

TRAINING FOR PROFESSIONAL TECHNICIANS!

Click this link to subscribe to the print or digital edition of Motor Age!

@@@@@@@@@@@@@@@@@

Due to factors beyond the control of Motor Age, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. Motor Age magazine (UBM Americas - Automotive Group) assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. Motor Age recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of Motor Age, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not Motor Age magazine or its corporate parent, UBM Americas.

[joemikos]

Thank you Pete, your videos have been a great help for me especially because you cover the fundamentals. I hade 6 ASE certifications which all lapsed in the 90s. I battled cancer for many years and put my wrenchs down over 20 years ago.
About two years ago I was too sick, (and too broke due to med bills over $70k p/y) to change the power steering pump on my 88 Chevy pickup.
I heard about a church that has a Car Care Ministry.
Long story short, I got in for the church's once a month Car Care event and was quite shocked to see a huge, well equipped shop with 4 lifts and a front end machine. I did my best to hold wrenchs and pitch in with the volunteers working on my truck. I had been in bed virtually for ten years but it was exciting being in a shop again.
Later on they rolled in 4 brand new tires. I hoped they weren't for me because I had no way to pay for them even though the tires on the truck were shot. Sure enough mounted them and put them on for me. When I told them I couldn't pay for the tires they told me not to worry about it!
I was so grateful I started coming in as a volunteer. In the beginning I could only work a few minutes at a time.
Eventually I got stronger, and started doing some real work.
Now I do most of the diagnoses and pro level repairs. I have been able to get scanners and other tools donated by well known You Tube mechanics inspired by my story. I recently took in, on behalf of the Church a Snap On scope from the 80s called the Counselor I believe. Hey, a pattern is a pattern right? I have ultimately worked on hundreds of cars including dozens of donor cars. I didn't expect to be alive at this point let alone building a reputation and helping people keep their cars on the road. I now have a future at 60 and plan on getting my ASE L1 ultimately.
Couldn't do it without the videos. Sorry for the long post but thought it might inspire someone to keep fighting even when there seems to be little or no hope.
Thanks, Joe

[carguy]

I’ve used it before, but never understood that a/c coupling was a fancy way of saying that you’re simply focusing on the a/c current.

Thank you - SO helpful!

[mike-ypuk]

Thanks i really enjoy the back to basic tests because it just solidifies the power of the scope. Pro's need this constant training to get the accuracy needed for todays cars.

[omareid]

I love this channel please continue in explaining scope for us until we become good at it
Thanks again

[henryrobinson]

these videos are good for the older techs too like me (55), just trying to learn the oscilloscope, done it for 40 years but they is always learning involved

[donniehayes]

Thanks Pete for taking the time to share this info in terms easy to understand. I have learned so much watching you over the years and look forward to learning more the most important lesson I learnt is you can never get to much, when we stop learning it is time to change fields because cars are always changing.

[tgoodm]

Great information!!! Please keep these videos coming on using the scope. I'm an aspiring tech. Thanks!!!

[numlock]

Thank you for taking the time to make these videos. I am sure that most of the entry level techs have snap on scopes vs Pico ! I myself am new to the snap on versus and really appreciate any training I can get on it ! Keep the training coming !

[davesministry]

Good video again Pete. You are an excellent teacher. You where the first video I watched after purchasing two of your DVD, s on how to operate the OTC EVO. There was, I think no avaialable information on it. The owner, s manual assumed you new the terms they where  using. You explain these term, s Thank you.

[jasonc.]

Hey Pete with using the ac ripple test at the battery like u showed. What if u have excessive ripple. U would suggest replacing the alternator right away because plenty u cant reach ur leads down to the alternator post to do direct testing. U da man Pete

[kevanpitt]

Thank you for take time make these videos for the entry level techs.I have a snap on vantage pro like to no how to use it. And get the best out of my two change scope! can for the next videos.

[richardmcwhirter]

great video thanks it really helps.sometimes we need to go back to the basics to relearn

[REPOOCNITSUJ]

Another great video! When you are hooking up the leads, and you say "hook up the other leads to the battery" (approx 6:45), are you connecting the green lead into channel #2 and the ground to the yellow lead? or just using the yellow lead?

[ronaldamodeo]

Excellent choice in scopes. I have used a PC base scope and a few others but I love my verus. Pete what is your preferred go to scope? Enjoying the segments..

[mugsymydog]

Pete ....I have the old version Snap on Modis with the 4 channel lab scope I am not able to get the same wave form you are getting. Is the Snap on veras a different lab scope then the one in the modis ?

[akaitv]

What's a cheap scope for a back yard mechanic

[Carlitosway]

What is an acceptable range for the AC ripple? Is it less than 1v or 2v?