How To Test Parasitic Draws Like A Professional!

This Ford Mustang came in with a massive draw that was killing the battery overnight. In this video you will get shown step by step on how to properly pinpoint a draw. The Professor will also discuss how things can change depending on the year vehicle you’re working on. And of course at the end of the day we will see what’s causing the problem on this one. Make sure to subscribe to be entered into the giveaway that’s coming at 100k!
Multimeter options:
Budget Friendly Starter Meter: amzn.to/4aZg9NT
Fluke Multimeter: amzn.to/3UX86La
Our Affiliate Store:
Autel MS909 Scanner: amzn.to/4bVbXQ2
Top Don Battery Maintainer & Jump Starter: amzn.to/4bW0dwB
Topdon Phoenix Lite 2 Scanner: amzn.to/3wJMEBz
Brake Fluid & Coolant Test Strips: amzn.to/4ayOQJS
5 Piece Protective Lug Nut Socket Set: amzn.to/453c4GW
We are partnered with AESWave. We've dealt with them for years and they are great people so please show your support to them! Our store link is:
www.aeswave.com/RoyaltyAuto
Yes we make commission on these products if you buy from these links. This supports the channel. We will never recommend a product that we don't truly believe in. This is just the beginning of our products. We will add more as we go.

[@edwardsweat9121]

The BEST training video on parasitic draw problem that I've ever seen.

[@SuperCadillac08]

The car industry needs more master mechanics like you. 👍

[@RandellToporowski]

How do you eat an elephant…one bite at a time. This was an excellent example of using a logical process to tackle a ghostly problem. No panic…. Just results and no getting lost in the weeds. Thank you!

[@jodydewald19]

Great video. I like how the dog was "checking" under the car for any issues. ;)

[@pontiacsrule8761]

Besides being a great mechanic, He is so patient. Great teacher. He knows right where to go to find problems.

[@WIFordMasterTechnician]

The 12 years that I have been in this automotive field, I never used the test light for a draw test. Glad I watched and learned something new. Thank you for the helpful videos as always.

[@danabbene6507]

I am glad I am not the only one that fights with releasing connectors!

[@garyalford9394]

Yes on older cars they get very hard to unlatch !!

[@dockerjade]

This is a process I've been through many many times. I wish I had this video to learn from 25 years ago.

[@johnrpizzaguy]

I remember buying my first Fluke 88 about 35 + years ago at $400 Again another great video, I just passed 40 years as a master tech but I still learn from a few KZbinrs. Thank you 😎

[@damiangrouse4564]

I bought mine in 1989/90. replaced one fuse and maybe 7 batteries and it finally died dead 6 months ago. sent it to fluke...short story...they sold me a replacement for $366.00 total. so saved a couple of bucks.

[@markmerrill794]

I ,am in a very similar boat as you.

[@TheRevolutionx111]

I got my first Fluke with "UTI" logo on it back in 1989, great meter. Wish I still had it.

[@edpauly1650]

That is really great!! Always room for more tools in my box like aeswave. I use to take old standard blown fuse remove the plastic top edges of the plastic to expose the upper metal ends. Then I would solder wires to the metal ends and use either different ends to adapt different ends for testing with a meter or probe, or different size amp CBC stud breakers to check electrical system. What is really Ironic my son called the same day of this video and said his battery kept on going dead on his 2005 Ford Expedition.I explained to him how to check for a parasitic draw and how to do it He found 2 parasitic draws. One was the rear wiper motor switch, and the instrument panel.

[@david600R]

Thank you for taking your time to explain these diags. As a new tech, I cannot get enough of these! Thank you!

[@johnrpizzaguy]

As an old tech focus on auto electronics, it’s allowed me to stay clean, make more $ and have a long career. Remember that power is just like water it wants to find the easiest way to ground.

[@david600R]

@@johnrpizzaguy thanks man!! That’s a good analogy. I like that!

[@StrongerThanBigfoot]

@@johnrpizzaguygreat analogy

[@shannonharris]

The path of least resistance!

[@johnrpizzaguy]

@@shannonharris exactly

[@Gareth-yr3vm]

Excellent method and a very logical and simple approach to finding the parasitic draw. I often follow that very same diagnostic approach, agree that on modern vehicles these kind of faults can be massively time consuming and frustrating but nothing is impossible if the approach is methodical and you stick to your diagnostic routine. The biggest piece of advice I can give after years of experience is keep it simple as many techs tend to over complicate things which often overlooks the obvious, and when fault finding is getting frustrating take a break walk away and take the time to think rather than go further down the rabbit hole.

[@badasssamurai4954]

I really like this channel. You are easily one of the ELITE wizards when it comes to diagnostics! I might be wrong, But the camera guy is your son? He must be a great mechanic in his own right! I wonder why he doesn't speak and bounce things off from? It would be cool to hear the banter back and forth!

[@crasher88]

we need a part 2 where you demonstrate how to check a module that is staying awake and causing the draw but not because the module itself is bad but because it is receiving a "wake up" signal from some other compnent or being kept alive by some external source.

[@theroyaltyautoservice]

That’s a great idea for a follow up video. We have discussed making this multiple parts. 👍

[@overload3996]

Insulation with jump leads. I have done this with B+, GND, and BUS. If no parasitic, or module shuts down, its external.

[@lpaulson1964]

You keep teaching us so much information about diagnosing problems on cars. The right way

[@dailydrive9003]

Radio guy here. I was screaming at my screen but you probably did not hear me. Great channel by the way.Thanks for doing this stuff. Yes radios can be very thin now that there is no disc drive in most of them. Just installed one just like that the other day in a Grand am. I also saw the subwoofer amps early in the video when you were looking in the trunk.Been there done that. also noticed they had been wet and were rusting. i would have suspected them them at first sight. Common problem in boat stereos as well. Even with "marine" equipment.Great video anyway that steps through the process from beginning to end and is really not that time consuming if a person understands the system and how to use the tools

[@twl10101]

I'm not a radio guy but when he opened the trunk, I also noticed the amps and had a strong feeling that could be the problem. When he was going through the wiring diagrams and came to the one showing the amps on the circuit, I was thinking to myself, look in the trunk at those corroded amps. But showing the whole process is great, as you stated.

[@davidsacco4860]

Very good diagnostic approach. Very good video. One thing I have noticed in new cars with remote FOB, is that you have to keep the FOB at least 25 feet away or remove the battery from the FOB to keep the car asleep. Or wrap it in aluminum foil and ground the foil to earth ground. Otherwise the car will wake up and you have to wait another 45 minutes to an hour for it to go to sleep again.

[@danielholter1861]

I’m just a diy-er but I really enjoy the no BS educational content you, Eric O @ South Main Auto, and Ivan @ Pine Hollow Diag provide at no cost.

[@jeffcompton6937]

You're forgetting arguably the originator and the best in that category. ScannerDanner no hate on the gentlemen you mentioned they're all phenomenal at what they do. Hopefully you're already following ScannerDanner.

[@danielholter1861]

@@jeffcompton6937 I know of him but never watched.. I’ll check him out and hopefully his content is easily digestible like these guys.

[@theroyaltyautoservice]

You’ll enjoy. All of them mentioned are great guys and have brought a lot to the table for this industry!

[@jeffcompton6937]

Love that you guys are so close to 100K . You guys deserve all the praises youre receiving. We need to highlight our industry professionals.

[@garysgarage3669]

I literally said to myself when you opened the trunk. That those rusty amplifiers were the issue. Sometime a good visual can save a lot of time. Great video!!

[@alirezajafari7070]

Such an amazing way to narrow down the roots of the problem professional staff, I am kinda a DIY car diagnostic but I learned some new staff!

[@user-rv4ob4tg9x]

Man did I learn a lot from this video. Thank you. OMG that radio… never seen one like that.

[@davidberry2542]

That’s gotta be one of your best educational videos! I think you did a great job keeping everything logical and in order, so it was really easy to follow along at home. With using a test light to show the current draw at the battery to free up your multimeter, I suggest that once you’ve established what the draw is with the meter, you can just put the battery terminal back on. That way, when you measure the millivolts across the fuses, you are getting the full voltage drop (which represents current flow). Any test light is going to add a significant resistance to the circuit which reduces the readings by an unknown amount, as demonstrated in your video. Of course if you have 2 meters, then measuring current at the battery the whole time is best because you always know that the parasitic draw is (or isn’t) still there. I picked up a couple of new techniques in this vid, so thanks heaps!!

[@user-on5om9qg1j]

Thank you, for your time devoted to making this video, much appreciated

[@JessClearyAutoRepairLLC]

Hi, if you look at a schematic for the amplifiers, I notice there's no keyed ignition voltage. It seems the amplifiers must be switched off either by lack of audio input from the speaker wires, or with the "audio mute" wire on pin 2 of each amp. I'll bet there's either an aftermarket radio interface module (the rest of the radio you referred to) to blame, or the aftermarket radio isn’t properly powering down the amps when the key is off. keeping both amps powered up all the time.

[@k6ul]

Exactly what I was thinking. Something needs to control those amps. It would also be strange to me that both amps failed identically (not impossible though). And, I ALWAYS suspect an aftermarket install. It’s crazy what people do sometimes. And in this case there may be some sort of incompatibility due to the way the amps power down. The radio component in the dash is just a head unit. Find the radio module and I’m pretty sure you’ll discover it’s the issue due to the way it’s wired or some other failure.

[@melissathompson7229]

It's not the aftermarket radio....they do have a turn on wire for the amplifiers.

[@JessClearyAutoRepairLLC]

@@melissathompson7229 what schematic are you using? Mine shows all power feeds hot at all times (on the factory amps). The turn on wire from the aftermarket radio wouldn't be used.

[@c-moneycantrell7681]

Possibly the person that installed the stereo used a power wire instead of the remote power wire. If they don’t have a power light on them it’d be hard to tell they were always on. I just don’t believe both amps are bad but they probably both got wet so possibly??? I noticed the amps immediately when you triggered the truck latch and assumed y’all already diagnosed it before shooting the video

[@stigbengtsson7026]

I,m not a car mekaniks, but I would have askt the car owner - Have you installed anything, or are anything done to the car recently - 🤔 ? - maby someone cangech an amp or something, and maby you then drive, you do not think that was an issue. Then the car was standing still some day, and youre battery is down. It's like beeng a detective 🧐 hmm lets see.....? Tank You sir for a informative video 😎👍 Whishes from Sweden.

[@DependableAutoTruck]

my first draw test was on a late model vw beetle that was a trip i was using All Data and one of the techs walked me thru the same way you did this one found radio and HVAC module both were drawing. those german wiring harness are fun. but got it fixed it had been to several shops no one could find it. thanks for sharing these videos help remind us when we have long times between draws thanks so much wish i was younger and could work at a shop like you have where quality matters. have only worked at 2 shops that cared one of them is mine

[@4gClearWimax]

I’m glad Clayton got a raise

[@TraverseNowhere]

Thanks for this video and all your videos. I enjoy thorough repair and diagnostic videos, especially DIY for your vehicle. Helps me learn to fix my car and even if I take it to a dealer I have a better understanding. I especially like the parasitic draw test video. I learned how to use my multi meter but not comfortable with all functions. Between this channel, Dave's auto center, Car Wizard, care care nut, Chris fix, 1 A auto, scotty Kilmer, etc. It really helps

[@michaelgill8220]

On some newer European vehicles It can take anywhere from 90 minutes to several hours for the vehicle to go to sleep and sometimes even have to shut off the proximity sensor and keep the key over 20 ft away in order for it to go to sleep and not wake up.

[@samyared5609]

Great logical and methodical approach... Thank you.

[@tonydowning1486]

great video, the gentleman was knowledgeable thorough and followed the flow charts and it all made sense. Thank you.

[@sscott65s1]

Best video that I’ve seen on parasitic draw.

[@jroberson1981]

Wow!!!! This is the best video I have seen and watched. Very informative and very detailed. Thank you so very much for this video.

[@anthonytimperio1254]

Thank you for taking us through this process.

[@MrBoomSkate]

I really appreciate the level of detail and comparisons you shown. Thank you

[@ThunderbirdRocket]

Dedication and customer care !! Thorough ! Thanks !!

[@BenKlassen1]

Good, instructive, suspenseful video! Thanks again!

[@abelleitao1710]

Very well explained, thanks for taking the time for making this videos

[@DD-gd3fr]

Fantastic systematic steps at a clear pace.awesome

[@Awesomedude237]

Very educational and easy to understand. Awesome video thanks

[@kennethmullen451]

I really appreciate this info you shared and how clearly you share it.

[@puterg0d]

When you first opened the trunk, I noticed those corroded looking amps (the one on the right anyway, and thought it was aftermarket at first) and thought "that might be the issue right there". Though, I do want to add that us average joes aren't going to have access to alldata... Though, this video was extremely informative, so thank you!

[@malibuStroker]

Great video! Love watching you work through your diagnostic process!

[@scottsheffield2594]

Great troubleshooting. You are great at explaining also.

[@masonmounkhaty2009]

Very good diagnose you make it simple to understand to fellow the step of diagnose thank you .

[@delcorick9967]

Absolutely hilarious! " saying there's gotta be more of the radio somewhere " Absolutely hilarious! They started making these radios short like that w no cd player and have bluetooth and sd card reader, so it saves them cost making them short like that but just hilarious your reaction! awesome video very helpful!

[@brianwadley4633]

Great work. working through the problem

[@Un_brainwashed]

Parasitic draw issues are challenging but fun at the same time. Please make more vids like this. Thank you for the awesome and educational entertainment! 😊 👍

[@burkestrand5070]

This was great! I feel more confident now. I promise I would put your giveaway scan tool to good use! Thank you for your videos, it's helped my confidence and skill level a lot.

[@thiagosilva2611]

Legend! Gave a big help how to look after a drawing with my car. Cheers

[@davidsacco4860]

Yes, I have seen several of those small aftermarket chassis radios. Most of the circuitry is on integrated circuits and surface mounted components which enables the use of a small chassis.. The drivers for the speakers have built in heat sinks in them so they don't need an additional heatsink attached to the chassis. They can power the tweeters, midrange speakers and the woofers. There are usually separate heat sink driver integrated chips for the woofers. The OEM radio provides a pre amp signal to the sub woofer amplifiers which is a low power signal. The sub woofer amps takes this low power signal and increases the power to drive the sub woofers. What may have happened, is when this aftermarket radio was installed it was sending a high power signal to the input of the sub woofer amps. The aftermarket radio itself can drive the woofers on its own, only not as powerful. Depending on how robust the inputs in the sub woofer amps are, it may have taken them out quickly, or over time as it overheated the sub woofer inputs. This may be the reason why both of the subwoofer amps went bad. On some of these small aftermarket radios they have a pre amp output on the back which can be used to send the low power signal to the sub woofer amps. Of course judging by the rust around those sub woofer amps water may have gotten into them and taken them out also. Very good video.

[@seannice1469]

Thanks for the tutorials.... Super helpful!

[@WayneRambo]

great job. guys ,very systematic ,great to isolate the cause ,love these videos on the UK keep up the good work

[@generationxdad]

Great video guys!!! I bought my own Fluke 88V kit in the mid-2000s when I was apprenticing at the Honda dealership and I absolutely love it and use it often!!

[@aosanchez5]

Thanks for such valuable teachings !

[@wingman8447]

Very good tutorial. Tough getting down to fuse boxes for me too.

[@saneil5596]

I like your thought process I’m from England and all your test procedures transfer over I like your work I’m a a mobile tech and have to deal with different types of problems every day

[@CarsYouCanFix]

Great demonstration! Even without the diagrams you could still apply the principal to every fuse, although would take a lot longer. Subscribed!

[@hugogomes2143]

what a great diagnostic lesson! keep up the excelent work!!👌👍 Thanks for sharing! 😉 All the best! From Portugal 🇵🇹

[@thomasriske1594]

Great video! As an auto technician I love when these type of issues come into the shop. Some of them aren’t so easy but it’s so satisfying when you figure out what the draw is.

[@kdmq]

Ivan from PHAD did a diagnosis on, what I believe to be around a 1998 Ford F-150. This truck had a special battery conditioning system that takes 45 minutes to go to sleep. Just thought I'd chime in with this, since it is possible for cars even pre-2000 to take more than a half hour to go to sleep. I could imagine a few other makes like Mercedes Benz also making a few such cars in the 90s.

[@TomLSTD]

I've been working on my own vehicles since before i got my license and I learned a TON in this video- thanks!

[@rayp.454]

Very nice real time diagnosis (that radio component is referred to as a head unit, and as you discovered the amplifiers are located remotely near the speakers...kinda like Bose systems that have the amps actually on the speakers). Thanks for the video!

[@ramonduran2516]

Keep up the good work inspiring new technicians in our field. We use the Cal-Van Tools Amp Hound Current Tester Parasitic Drain and a Diagnostic Thermal Imager | Snap-on.

[@galemyers7397]

Thank you great video as a retired tech I wish I would have had those type of diagrams available when I was working. I still picked up some use full tips

[@trekOCLVone]

congratulations on getting (almost) to you goal of 100k subs. Great troubleshooting videos that you share with us. Troubleshooting skills are part training and part experiences. You are very good with both.

[@prasanthmoolethodi3152]

Thanks for the informative video!!

[@djkilleen876]

It’s so important to understand how the system is supposed to work before attempting to diagnose. This was a great video of common sense diagnostics. I use an amp hound or scope to do this but this was a great lesson I’m basic diag with little tooling. Awesome job

[@williamtherriault335]

This is a great video. I'm a tech at a Subaru dealership and SOA has been putting out training videos for refreshers on voltage drop. The most recent video showed how to do the same method of testing for parasitic draw that you show here!

[@alexanasta7578]

So right and so simple method. Very good job, i just wonder if we should try to repair the amplifiers or just get new

[@johnlenoir1023]

That was extremely interesting as I am learning this stuff every damn day it is something else the methods that can be used

[@jamiewatson536]

Great run down

[@StrongerThanBigfoot]

Love these videos especially learning to be better at diag

[@vendettaassassinpb6351]

Amazing video, learning a lot of techniques, keep the videos coming.

[@jgeorges3061]

AWESOME APPROACH AND THOUGHT PROCESS THANKS FOR SHARING. CHEEEERS FROM ONTARIO, CANADA.

[@unclemarksdiyauto]

Loving watching your procedure in testing this draw. Great idea with the tablet. I know you didn’t explain or show you doing it, but I see you used your edit tool on tablet to mark off each fuse checked and done. What a nice simple way to keep track of what is done and not waste time rechecking a circuit! (Video paused..back to your video!)

[@johnchambers12]

Thanks for sharing your thought process , i have seen this test process before but those amps look a little rusty to not be an issue! I have 3 DVM’s for the simple reason i have needed 2 to test before. And one is a Fluke and it is my favorite!

[@ronsta2552]

Yeah I did like it. Start to solution, Seeing how you determine your order of the procedures you use is reassuring that I am on the correct path. Thankyou, Great Video.

[@heathatkinson6445]

Really enjoyed that. Learnt a new skill. Cheers.

[@sheerwillsurvival2064]

More of these please. Excellent

[@craighancock1777]

Awesome stuff and very helpful

[@edpauly1650]

Thanks for all your great information. I'm always looking at being a better mechanic. I mainly work on lawn and garden, tractors, and light construction equipment. I do work on my own vehicles. Electrical issues can sometimes be a real pain in the B_ _ _ _. to find.

[@yaseenhashim8538]

thanks excellent diagnosis

[@hotrod49286]

Great tutorial, thanks!

[@jeremiewampler]

That’s the new style radio, no cd player so no need for it to be a cd size…love the information yall are providing

[@alanw9295]

Great diagnostics, love your vids

[@bobbyboucher3718]

Would've been nice to have teachers like you when I was young!

[@highrev90homemechanic67]

Looks like one of my comments was deleted. That is a digital media receiver. Does not play CDs. I was suspecting the amps as soon as I saw them in the beginning of the video. Very informative. Taught me A LOT about testing for draws. Thanks sooooooo much.

[@josephchamberlain9129]

Enjoying your process

[@vickenkaragozian2041]

I use Es 688 amp probe which has big jaws to go around battery cables for parasitic draw and i use ES 687 for small wires like in this case i would use on vt/lb wires on the subwoofer to see which one has a draw. I don't like using my fluke 88 to check the draw just in case the amperage is too high to blow the fuse. Thank you for posting another great video.

[@JP67521]

Great instructional video.👍

[@jpol3808]

Great video. Excellent content! I find with the fluke that using a set of test leads with the extra long needle tips, that have a super sharp point, I get a solid reading and it's a lot easier to reach under dash boxes with them...... Especially being an older guy who doesn't bend very well anymore! When you get really good at using them they are like chop sticks and you can actually test fuses one handed! Thanks for the video! J Poll. 👏🏁🇺🇸.

[@Mr2004MCSS]

I like using an amp clamp meter set to DC amps around the positive battery cable with it still attached to the battery and a regular multimeter to test across the fuses to find parasitic draws. This way you don't have to take anything apart. Negative battery cable is also left attached to battery for this test. I just bought a relatively cheap clamp meter off of Amazon because when I learned about this method, I didn't own a clamp meter. Nice video by the way.

[@johnyoung4466]

Great Video, my dad had a draw on a 2011 Ford Fusion shop never figured it out. We figured out ourselves that the radio was coming on overnight and killing the battery. By making sure that the radio was turned off before turning car the ignition off problem went away. Factory Radio.

[@martylandry751]

Thank you, Great Work

[@antonioclark404]

Takes time money saved thanks

[@alexron2023]

Water has been protruding that area, see how rusty the amp covers are. Imagine how the electronics could be inside those amp. New radios without a cassette or CD player are very compact. The old radios were big just to accommodate the transport system. Good video, I always enjoy watching you explain the procedures

[@jnb8918]

Great video. As an industrial electronics technician, I didn't even knew there was those voltage drop charts for automotive fuses. Great thing to know ! About the amplifier problem, both having about the same parasitic current draw, I assume they are not "bad", very improbable they went "bad" by exactly the same amount of parasitic current. I assume they are powered up all time by an incorrectly wired "wake-up" signal. Probably the aftermarket radio wake-up signal was incorrectly wired or not compatible. Thank you for this instructive video !

[@crs768]

First,,,,, To Say Thank you For Your Content

[@noels2]

thanks for info.