I'm a 9 year VW/Audi tech. This was an excellent explanation of measuring for a parasitic draw. I'm going to show this to my apprentices. Great demonstration of knowledge!
From a former tow truck driver, you would be surprised How many vehicles have a parasitic draw. Thirty days on the lot and the battery dies on almost every vehicle.
theres a bunch of electronics it wouldn't surprise we if theyre actually just in standby these days i mean if you disconnect the battery the PCM forgets learned memory so... scale that up right?
Pretty much all vehicles have some parasitic draw, clocks, radio memory and rke systems. As long as the total draw is under 50mA, that's generally considered acceptable
@@jba6677 Cal-Van makes a slick tool called "AmpHound" that does this for you. You punch in what fuse size/rate you're looking at, put the probes on the test ports, and it tells you how much amperage is running through that fuse. I love mine, can do a whole fuse panel in about 2 minutes.
Dont pull fuses. Some modules will reset once they see voltage again and enter an active phase. Do as @jba6677 said. Measure voltage drop across the fuse. To do this, set multimeter to mV setting and put the leads to the metal probe points on the tops of fuses. You then look at the chart for a given rating As a 5A fuse will drop more voltage drop than a 20A one even for the same current draw.
Why pull fuses? Every 2 prong auto style fuse has 2 terminals on the top of the plastic body of the fuse. Just set ur meter and check for voltage on both sides of the fuse via the top terminals.
That can slowly be figured out too by removing one fuse circuit at a time, generally. The trickier part is finding out which thing it is on that fuse chain. I know some folks that just have a switch to that affected fuse chain as they didn't have the money needed to figure it out.
Parasitic draws aren't super common but if you're doing a lot of that kind of diagnosis then a thermal imaging device would cut your diagnosis time. It is expensive but it can save you a lot of time in the future. You just look for which circuits stay hot on the bjb or bcm and start narrow it down to 2 or 3 fuses instead of 50 or 60
Agreed 👍 . the first thing I would do is check inside the vehicle to see if there's any accessories that are still plugged into an auxiliary power outlet ....ie, a phone charger
Which is why you then start testing circuits starting with accessories and lights. You can also research if there are any common issues for your vehicle like GM half ton chassis having failures of the trailer light block fuse
I recommend leaving all doors open but locking the latches. This way modules think its closed abd u have axcess to the interior in case issue is inside. Like interior fuses, cig lighters, etc.
@@PW_12345that’s a good tip also for the vehicles that are not built into the latch. Usually Hyundai and Toyota. I just latch the Audi and vw cars since they are in the latch.
Nearly all modern Toyotas have the door open/closed switch on the B pillar. If you leave the doors open the system will report just that. Also, on most current Toyota models if a widow is down it will also trigger the a sensor. These will continue to report (drain battery) until the condition is resolved.
Subaru had an issue with this, dealership couldn’t find anything wrong first two times…until they found it. I’m going to send them this so they can learn from Faye like the rest of us
Subaru basically just figured this out. It's the DCM (telematics module) that's running the batteries dead. Basically, they pushed out an ota update to every car that was subscribed to starlink a few years back. When all the cell companies were turning off 3g, the update made it so the module could use 4g now. I guess the hardware was there but not the software for some reason? Anyway, if you weren't subscribed to starlink before they shut down 3g, your DCM can now no longer connect to any tower, but it keeps trying periodically anyway. It does this in random intervals, so it's entirely possible to do this test and it passes, but 2 hours later it decides to try and ping non-existent cell towers for 3 hours, and eventually killing your battery. The fix is to buy a new DCM, to the tune of about 500 bucks. Or buy what is essentially a Subaru official DCM delete kit for 200.
My 18’ forester battery dies every 3 days if I don’t drive it, they say it’s normal cause of all the accessories. I eventually replaced the battery guess what no problem since. 😂
It's nice to see techs actually diagnosing a problem rather than throwing parts at it. That was my pet peeve as a diagnostic tech. With dead batteries, techs will often throw a new battery or alternator at it. I don't like parts cannons. Not only are they not doing right by the customer, but it will end up in my bay when it comes back. Good work.
Yea I hear that - I was a mechanic in the Seabees & sometimes we could troubleshoot by switching parts though. Thats only because we had 10 of the exact same peices of heavy equipment there.
My favorite multimeter is my DC Amp clamp so I don't have to physically plug inline with the circuit. It's not quite as accurate as the physical connection but it's served me well and takes but a second to put inline with the circuit. It's also phenomenal for solar system diag for my van.
The newer vehicles with the SOS system suffer parasitic draw at a very high rate. I actually did an overnight test because some of those modules power down after four hours. Toyota even gave me free access to their information systems because my certified used 4Runner had a problem. After a year of owning the car, they bought it back from me, they agreed that I found a bunch of problems with it 😁. Turns out, it was a former rental car
I bought a new vehicle and I did this test, waited 2hrs and got a reading of 71mA. I too used a fluke 87V, did this test so that if I had any problems in the future I'd know...
Great! But 2 things to add to this. 1) disconnect battery first. Use a jumper cable between the battery post and the battery cable. Hook up the amp tester connections at the post and the cable at the same time. Leave the doors open and trigger latches so the modules thinks it closed. This way you can access testing points without trigging things awake. Once the half hour wait is over, disconnect the jumper cable. The tester is already hooked up. Wont risk an accidental disconnect during the cable/tester transfer. 2) next level pro way of doing this even quicker. Requires a thermal Imager. (Works better in colder climates) Again, set up vehicle with doors open and latches triggered. Hood up and latch disabled, etc. Then hook up a battery maintainer. Go home for the night. When you come back the next morning, inspect the vehicle with the thermal imager. Whatever is causing the draw will still be warm. It will be obvious to find (unless its super buried in the dash like a body control module). I have found many battery drains this way. Super quick as it only takes a few minutes to set up the night before.
Here’s a mistake I see often, they see the draw, then after inspecting circuits, the meter shows no draw. They didn’t realize that when they opened the door the excessive draw popped the fuse in the meter
Even though older cars have fewer things that can cause parasitic drain, it isn't impossible. Shorts can still happen causing circuits to remain on unnoticed. If the wiring hasn't been upgraded it can be more common. My pickup had a parasitic drain from the ignition module and it's a 1971.
The person who invents a add on self driving computer to older cars will get me to daily drive a 90s toyota and maybe a domestic truck till the day i die. A system would be aftermarket needing a strong stepper motor attaching to the steering column a new electric power steering pump with some solenoids, a camera, milimeter radar ,and probably a new brake booster and access to the brake lights and turn signals.
The miliamps really depend on the vehicle, also a lot of vehicles take over an hour to fully go to sleep, some of them also won't sleep unless you close the hood latch.
Hi whatcha up to hope all is well sending up prayers 4 healing and unspoken and 4 everyone and bless great healthy peaceful safe journeys travels and happy day everyday in name of the Creator God/ Yahweh and Yeshua/ Jesus and the Holy Ghost/ Spirit Amen much honor and respect keep walking tall always yall also how do u chk to see if ur flasher is bad and can u get a more higher output/ more hvy duty flasher just a question ?? 🕊🦅✝️💪🙂
Like this gal here but don't like is she buying stuff from Amazon a un-American salve company...hope she finds a better source for tools like a specialized electronics house or even pay the devil snap on
This is a good basic idea to do this test, but incorrect. You need to install a battery disconnect or a jumper wire first in the system. This way you can easily control the connection or disconnection to the battery. Also you need to use a test light or an amp clamp with the disconnect installed first, in order to verify the current is low enough to test with your meter. Otherwise, you will pop your meter fuse many times and waste money and time testing too high of draw on your meter. Also, open the doors and relatch the door latches to make the interior accessible while you're testing.
I showed your videos to one of my friends he's an automotive instructor at a high school. He's been showing your videos to his students for a few weeks now, and he absolutely loves that your shop and yourself are so clean and professional. HE doesn't like to show videos where there's a filthy shop and a dishevelled worker, he teaches all of his students to be clean and professional.
Another fantastic mechanic is out of Centerville Utah. The guy's name is Dave. Really clean cut and precise. You can tell he is extremely passionate about his job and customers. As someone on the spectrum, I swear he is on the spectrum too. Watch enough of his awesome videos and you'll see what I mean.
Nice i never thought about the keys. I use my jump pack temporally to make the meter connections on the harder ones like side post. 50ma is to much i like to see 25ma or less.
No, just selective about which pieces of equipment that I buy which are Fluke. Not every meter or device I own is Fluke, though that doesn’t keep me from dreaming.
Dodge caravans are famous for this. My dad has one where he chased it for months. It turned out that after being off for hours and even days it would randomly turn on the fuel pump then kill the battery. There are kits online to tie the pump in with the ignition switch and bypass the main module. Fixed it right up.
I’m curious, my Audi has a fairly new battery and it just drains super quickly my best resort has been to just disconnect it every night, the alternator gives it enough power to go throughout the day but usually I have to jump start the car and I’ve charged the battery several times but it still just drains so much power,
That's a heck of a drain. Any aftermarket stuff connected or plugged into it? Interior light switch is not left on? Stop at a chain auto parts store and have them test the battery for free. If you're dreading getting it diagnosed and fixed, you could use a battery tender overnight instead of disconnecting, but that's not a real fix. It just prevents loss of presets and other information when the battery is disconnected.
do you by chance have the hood not fully latched? I did that with my S4 so I could more easily open the hood and remove the trickle charger. But, it turns out the hood latch had a sensor that had a constant 80mA draw (but no dash lights, interior lights, or any other indication that this was not something the computer wanted me to do). If it's not anything easy like that you're probably going to have to check each fuse and relay
Make sure NEVER to apply voltage to your DMM in parallel (like across battery terminals when you measure a voltage reading) while you are in current measuring mode. You will blow a fuse or if not, damage your DMM. 👍🏼
@@MotorSwapDan Fluke fuses are expensive, why blow them on purpose? Also, it is not guaranteed to blow in time to save your meter from getting fried while it has a low internal resistance. HOPEFULLY it does but you cannot assume perfect fuses.
Love your content and accuracy, you always nail it! Also, an inductive mA clamp would work in this case, thus avoiding the need to disconnect the negative post. Sometimes having to do extensive resetting if connection is accidentally lost.
When done pull out those multimeter leads because voltage checks with leads in the amps sockets are a direct short circuit that cooks your meter. I wonder - how did I know that.
This isn't the proper way. Leave all of the doors opened with the latches closed don't close all of the doors and lock it 🤦🏽♂️ can't believe everyone is saying this is good
Oh I do not like that. If you really want to do an amp draw test and DC, don't use a multimeter, even if they say they can do 10 a mcs, they can do 10 amps for about a second professional dealing with fluke at the prices of fluke, and yeah, flu can do it a little. Better blah blah blah. But literally four a tenth of the cost of just the fluke probe said she bought, she could have bought a very simple, dc Ant meter module. But let's be real. It's that aint the right way to do it because okay, you did all that work now. You know, you got a parasitic drain, and now you gotta go figure out where it is. So through that test, actually did you no good, but a waste your time? And if you're charging the customer on an hourly diagnosis rate. You just ripped off the customer. Hopefully you didn't build them for that. And then you have to go and take your multimeter and Check each fuse. There are ammeters that plug into the a few suck it.But you don't want that because that's gonna trip something up But also really, if you're having a parasitic draw, I would be checking for bad grounds and ensuring call. Mike connections are solid because even a corroded fuse contact Can cause a so-called parasitic drain because it's taking more current to get the current the. Uh, this module and Sleep mode needs. And then, depending on the car
This is when you just buy a portable battery charger and make sure to run your car everyday and also put on a battery cut off switch for storage. Cost 10 dollars, put your car in the woods for a month, turn the switch, and its just about as good as when you left it no matter wha
50mA is nothing, even 150 considered kinda ok. Remember, batteries have 100 Amper Hours, so it wil be drain with 100mA a thousand hours. It's about 40 days.
Based on some viral vids lately, check for those pesky "deactivated" GPS trackers that some lots will install. If you decline to purchase, they'll deactivate but not remove them. That doesn't stop the electronics from consuming "some" power.
Done that many times! Always remove the lead from amp socket after testing! I bought a 10 pack of 11 amp fuses from Amazon. 70% less expensive than the "tool truck"...
Check for an unauthorized GPS system. The dealer, bank and insurance company want to know where your car is and how you are driving. You know, in case they need to repossess it.
Keep the meter connected and start pulling fuses 1 at a time. when the amperage drops below 50 mA, you found the draining circuit. Mine was the factory Bose Radio.
Next put that meter on the mV range and measure the voltage drop across all the fuses. Each fuse is a low value resistor, so you can actually find when the draw is from. High amp fuses have lower resistance.
Careful going straight to the DVOM. Last time I did this, it popped the fuse in my Fluke. It was more than 2 amps. The other way, if it is a pretty high draw is to use a test light.
It’s so much easier, and safer (equipment wise,in general) to use an amp clamp for ANYTHING amperage related. Even the best DMMs only go up to 10, or 15A, and even though you probably won’t be drawing anywhere NEAR that in a parasitic draw test, it’s just good practice to rely on your amp clamp, in matters of current, in my humble opinion. -thank you for listening to my Ted talk.
Yeah...your clock is still running. The security system is still running. ...and how many phone chargeers are STILL plugged in! I have a Pacifica. Not the problem. It's in VERY good condition! I drive a beat up minivan for work. Car is in garage with security system on. Dead battery in 1 month.
Just get your volkmitter Is take a reading when you shut the car off Take another reading forty five minutes later If the volts having gone down bad thang
THANKS for a good explaination AND providing an expected high value!. BE CAREFULL with the leads in the meter and what is being measure. I smoked a DMM switching/wanting to recheck battery voltage
Okay, I was told by my Toyota dealership (let's call them global) that my battery had a warranty and to bring it in and I will get a discount on a new battery. Toyota uses fuzzy math when they have to determine the warranty for the battery. It turns out I would still have to pay 80% of the cost of a new battery. So I told him that's okay I'm just going to go to Napa to buy a new AGM battery. They said well you're going to need a technician to install it because the battery has to be compliant with your cars computer algorithm? He said because if it's not it will prematurely wear out. I installed it myself, It's been a year now I haven't had any problems.
Well I was trying to watch this because I was dealing with battery thing. S but it was kind of hard to pay attention to your video. No offense, I love you tattoos, but your eyes are incredible. No, I'm not hitting. On you. I'm just letting you know. It was kind of hard not used to seeing beautiful mechanics. I look forward to seeing more of your videos.😂😂😂😂😂
My work buddy worked on a car that drained the battery overnight from a full charge. That’s what he did. And after all the modules went to sleep he noticed a 58mA drain. Then it spiked to 4A for 30s and then about 100mA for 13s and then 58mA and almost immediately back to 4A and it cycled like that. It turned out to be a faulty switch in the driver’s seat control. He disconnected the cable to that motor until he could source a replacement switch. No more drain.
I had to pull up at TSb yesterday for a 2016 Ford escape for a company that we do work for it was one of their fleet vehicles. It turned out that the battery was going dead every three days we had this happen for about a week after that, I decided to take the vehicle for Further watch and we pulled up the TSB to see how many milliamps it called for when It went into sleep mode so it’s 45 mA and it was doing a parasitic draw 300 mA, so it’s basically like leaving the car doors open for three days straight turned out to be the tracking beacon inside of the vehicle that they had wired up through the OBD two port and running back to the fuse block. It was one of 2 tracking beacons and they wired the new one over it. Needless to say the car was never going to go into sleep mode. Would just stay under 400 mA
Similar happened to me. Truck was eating batteries. Culprit was my enormous after market audio system with amps and sub. I swapped in a high output battery and installed a more powerful alternator. New terminals. Fixed loose connections. Solved.
Love my old toys. All you have to do is, put a 12 volt light between the battery cable and post. If the light is on, something is on. Pop the radio and clock fuses and the light should go off. If not, a trunk light, hood light or something else is draining the battery. If the light was off, just pull your headlight switch to park position and the light will come on. Once, I read voltage across the top of a dirty battery. It measured the same as the post to post voltage. Washed the battery, removing what was left from charging cycles, and the drain problem went away.
Instead of that tricky handoff while disconnecting the battery, get a short length of heavy guage wire with 2 large alligator clips. Disco the battery, reconnect with your jumper. Do all your prep and hook up your meter. Now, the battery can be connected/disconnected as needed - no Indiana Jones switcheroo skills needed.
Those new age load testers are absolute junk. All it does it put a 1-2 amp load on it, and bases the voltage drop over X time via an internal algorithm to determine if the battery is “good” or not. What it doesn’t test for is collapsing cells which does happen a bit, thus assholes like Autozone’s won’t refund or exchange the battery because it TeSTs gOoD 😂
Girl.....lab scope set to 20 amps, low amp probe around the negative cable, and a thermal imager. Leave vehicle alone for about an hour , and then use the thermal imager to check fuses for heat disappation.. I charge 3 hours for electrical issues as it can take most of the day in order for a module to "Wake Up", and show signs of parasitic draw.
😂😂😂 Yes I have a parasitic drain but I didn't want to find it. I have a remote battery disconnect and now the parasitic drain is no problem and the radio keeps its programming still. But, I have to put a new harmonic balancer with the weight. My balancer weight broke and is wobbling. 😂😂😂
My c230 coupe, 2003 has a newer battery. It dont like to start after 3 days of sittiing. No codes. Battery, alternator test says its fine. But, I have a Viper alarm, custom soundsystem. Starts fine every day, second day of sitting.
I like to watch girls play pretend. What ru today hun? Oh a big mechanic. How nice. After you break everything on the engine go makey me a sandwich and I'll fix it for ya. We'll tell everyone you did it though just like on all the reality shows.
Hey Faye, great how to. it’s funny just how smart cars are. it does take some devious thinking to trick them which is right up my alley, the devious part anyways, but don’t worry I only use my powers for good🙂🐔🐔🐔👍
17 minutes for my BMW e46 is how long it takes for all the modules to shut down. It's about the same for my mates e90 3 Series. It's best to wait 20 mins before testing otherwise you will get a wrong reading.
She gets you to the point where the parasitic drain is determined. But that's just the tiny part. The red LED that's seen blinking in some cars can draw up to 10 mA or sometimes a bit more, but it usually blinks on and off. The radio or similar electronics can draw a small amount of power. There is a clock that needs some small amount of current. Other electronics, especially the microcontrollers can draw a small amount of power. Finding the parasitic drain can be difficult. All current goes through the fuse box so pulling out one fuse at a time can lead you to the approximatelocation of the parasitic drain. Then even more detective work is needed to find the exact device that's causing the parasitic drain.
Narrowing down the problem is where it becomes a pain in the ass. I have a 06 Cadillac STS that I am basically junking. This is one of the problems that it has. the others are bad catalytic converters, drive shaft bushings, timing chain and it loves to drink lots of gas
Open the driver door and close the door ajar switch when setting up. Once the vehicle goes to sleep you'll wake it up again having to open the door to pull fuses. Also 50 mA is depending on the reserve capacity of the draw, usually half of reserve capacity is allowable draw
I did it this way for forever, until I bought the low reading amp clamp from snapon. Expensive, but well worth not popping fuses, because the water pump is turning itself on....
If bean counters and Engineering Departments. Had to spend 3 to 5 year's working at Dealers Shops. Cars would be way easer to work on and stupid ideals on cars would stand about as much chance as an Ice cube in hell. As bad ideals on the drawing board reaching the production line Good job
Instead of using a ampermeter,use a Dc clampmeter,you dont have to disconnect the cable ...And up to 60-80 mAmps is not too much... Dc clampmeters are cheap now.
If you have ANY miliamp reading you have a parasitic draw. When the car is off everything should be off within 15 minutes no matter the year make or model, if not time to hunt a draw. People say fuel pump modules or memory modules dont ever turn all the way and thats bs. They have 5v memory batteries in them that get charged everytime the vehicle is running and once the car is off they use the power off those memory cells.
I worked for Toyota for 25 years, this young lady is smarter than most of the off line people their. Usually it's the a$$ kissers that got those jobs. Management made them special so they didn't follow their own Is seniority rule
Your theory is good. Your technique could use some work. Latching the hood latch on many vehicles doesn't do anything - they have a plunger switch on the core support. And instead of doing that finnagle with trying to lift the battery cable off the post while attaching your alligator to the post, install a back feed into a spare hot at all times fuse in the fuse block put your meter from that back feed to the battery cable. Then pull the main fuse on cars equipped, or lift the fuse supply cable off the fuse block on cars without a main fuse. No finnagle required.
If 30ma drain is flating your battery in three days,your battery is crap. Check your alternator, and the age of the battery. If the battery lasted only 2 1/2 years, buy a different brand. I paid the difference and have a decent battery, and magically i have no problems at all.
