Usually the issue is with the "new' variable charging systems. The alternators dummy down to supposedly save you fuel, but in fact it does not keep the battery fully charged. Disconnect the the black sensor at the negative cable to disable the 'variable' part, and it will act like a normal alternator providing full charge all time. No this does not hurt your battery, there is a regulator in all alternators to prevent over charging. Very common mod with newer vehicles. The more gimmicks they create to save fuel, the more issues you will have. 😛

@DadsGarageDiagnosticSpecialist

Ай бұрын

Yep all these complex systems to save a penny in fuel have greatly reduced reliability. Thanks.

I haven't read all the comments, but has anyone mentioned that there's a class action lawsuit with Subaru about parasitic battery drain on some models? I have a 2019 outback and have had problems with dead batteries several times. The first time, the battery was charged by AAA and the car worked for several weeks, then it stopped working, so I had a new battery put in. The car worked for a couple of months then again, it wouldn't start. This happened several more times. No mechanic could figure out what was going on, then I received a postcard from Subaru about the class action lawsuit (unfortunately, the lawsuit deadline closed March of 2023.) Apparently, several models of Subarus starting with 2015 are affected with parasitic battery drain. Someone explained it this way: When you shut the car off, Starlink and some of the other electronic features stay awake and can drain the battery. It's so frustrating. I had a 1997 Subaru Outback that lasted for 22 years. I had very few repairs on it. Granted, it was made before cars had all the fancy apps and gizmos they now have. But at least the car ran.

@DadsGarageDiagnosticSpecialist

5 ай бұрын

Very interesting. Thanks for sharing!

@mikam8801

4 ай бұрын

Yep. Some are pulling the DCM fuse for cars sitting for too long without starting. - And don’t leave the hatch open for too long, that will also drain the battery.

@Nemesis-yn5wv

4 күн бұрын

The starline system is trying to connect to a 3G network to “check in” that no longer exists. 3G was shut down. A software update or new part resolves it.

I inherited my father’s 2019 Outback wagon upon his passing. Sat for like ever. I drive it three times a week and had to replace the stock battery. New battery like others have said in the comments worked for months and then all the sudden after sitting for 2 days is dead dead. Jumped it and hoping it’ll be ok for awhile. Alternator shows it’s putting out as it should. So it has to be a parasitic draw issue.

@DadsGarageDiagnosticSpecialist

6 күн бұрын

Interesting… I wonder what could be going on. Thanks for sharing!

I have a 2021 Subaru Forester that would have a dead battery occasionally, not every night. It doesn't always have a bad draw going on. The battery was defective. I replaced the cheap Panasonic battery that came with the vehicle with X2-Power AGM battery - problem never occurred again. Your "fancy" tools don't always show the problem. Just replace the customer's battery already rather than accusing him of being the problem.

@DadsGarageDiagnosticSpecialist

6 ай бұрын

I wasn’t really accusing anybody… from my perspective I have no idea what the vehicle has been through before it arrives at the shop. This one never had any further problems so I’m not sure how the battery ended up dying. Thanks.

My 2019 Subaru crosstrek battery would die every few months… jump it and run it a while and it would be good for another few months then dead again… alt at 14. plus volts…of course no answer from the dealer. I recently received a letter ref a parasitic drain by the DCM. I made an appointment for this Friday…. they want me to bring in the letter from Subaru .. not much confidence at this point.

@DadsGarageDiagnosticSpecialist

3 ай бұрын

Apparently, it would seem this is becoming common on these vehicles. Thanks for sharing.

We've been having nothing but problems with the battery in our 2021 Crosstrek 6MT. At one point it was discharging in a few hours because the radio was stuck in a reboot loop and not actually shutting off when the car was parked. Subaru replaced the radio and that stopped happening but the battery still slowly discharges and needs to be recharged once every week or two. I am replacing the poor Subaru battery with a 640 cca AGM battery today to see if that helps. The car is driven 5000 miles a year on average which is not a lot but I have a Miata that I drive less than 500 miles a year that doesn't have these issues. One possible cause is that I heard that perhaps Subarus don't charge unless there is a certain amount of current draw which could result in a gradual loss of battery charge without the car attempting to recharge it. The solution oddly is to leave your headlights on during the day which will flip the alternator into recharge mode. This may be an old wives tale though but it seems plausible.

@DadsGarageDiagnosticSpecialist

6 ай бұрын

That could be plausible with the headlight thing. The charging system may stop charging at certain times to save fuel, but if the driver has requested headlights the charging system will output usually 13.5V-15V to keep the headlights at full brightness. Thanks for commenting.

@kevind.5246

6 ай бұрын

The Starlink (Telematics DCM) system is notoriously prone to high parasitic draws. You can remove the DCM fuse to test (It's always on) . Aside from a defective unit, seems it's sometimes a problem with an internal DCM 3.2V battery though surprising since a 2021 is fairly new. It's an issue w/ my 2018. One work around is to tap to an ignition on spare fuse but Starlink would only work w/ ignition on.

Been there done that with 2017 Sub, I now have to turn off all interior light, drive with headlight all ways on, never use the rear hatch to unload and do not leave the forester until pax side mirror goes out. Man do I love these new cars with all the bells and whistle with the cheapest battery ever made.🤕🤨

@DadsGarageDiagnosticSpecialist

7 ай бұрын

Thank you for sharing! I recently had a brand new Toyota rental car at home, and I walked outside at night after the car had been off for several hours, and it was making all sorts of noise with pumps and stuff running doing self tests at night. These cars are loaded with technology these days.

Multimeters don’t really pick up the draw from the starlink system as it uses power in pulses. A picoscope picks the little spikes up easily.

@DadsGarageDiagnosticSpecialist

3 күн бұрын

It’s an absolute must these days. Thanks.

My 2016 6 Speed has the same problem. Battery is constantly dead after 2-3 days. I installed a maintainer. Also was looking into Lithium Ion car batteries since they charge so much faster than lead acid. Decided to still stick with lead acid, but bought the most expensive AGM East Penn makes. Guess what...still dies in 3 days. My battery has been dead at least 20-30 times.

@DadsGarageDiagnosticSpecialist

5 ай бұрын

It sounds like you have a parasitic drain that needs diagnosis. Thanks for commenting.

I have a 2017 Outback. I have had an issue with a dead battery. Brought it to the dealer they spent all day on it to find no problem and to upgrade the software. (There were two others in the customer lounge with the same dead battery issue). On the Outback forum there was a post about driving with your headlights not on automatic but on manual. I also saw a post on KZread where the car owner bought a car charger that plugs into your power port that has a voltage read out on it. The video shows when on automatic engine running the smart alternator was only putting out 12.1 volts. With it turned to manual the voltage was 14.1. So I thought I would buy a car charger with voltage readout to monitor my voltage. I found the same issue. On start up with headlights turned on automatic the alternator started charging at 14.2 then a short time later while driving went down just over to 12.1 volts. To me that’s not enough to keep the battery fully charged. When a healthy battery should read 12.7 fully charged. Sadly I don’t leave home without a fully charged battery pack any more. Sure wish Subaru would step up and find the issues with these cars. Three of us in the customer’s lounge in one day?

@DadsGarageDiagnosticSpecialist

7 ай бұрын

That is very interesting. That highlights the need for a good healthy battery if the charging system is going to undercharge for the sake of fuel economy. Thanks for sharing.

@jnsadavis5978

6 ай бұрын

This is a well-documented ongoing issue with Subaru electrical systems that brought about a lawsuit. I went through several batteries in a short time and a parasitic draw within the electrical system drained them all. I have come to expect to fork out $ for a new battery once every 6 months to a year. My next plan is to have Subaru update my alternator software and move to a more powerful battery to avoid the drain.

@Teenagegoogoomuk

6 ай бұрын

My 2019 forrester has the battery draw but hatch works fine. I tucked a $20.00 battery maintainer under the fender well and just plug it in after driving like a EV. Yes it's plug is setting in the wiper blade trough driver side and rain wont bother it in the rain since it's not plugged in but I haven't had to jump start it in 6 month's. Those that don't have a garage no problem either just keep the plug covered and it will be fine. Wal-mart Everstart trickle/maintainer. I bought this car for my wife and she doesn't drive it everyday. Sad because it's a very nice vehicle with ugly problem but this has been working for months so I permentally installed it in the engine bay. Yes I spent over $500.00 on this problem with new battery and all only to come down to a $20.00 item

@jimettamarna417

6 ай бұрын

@@jnsadavis5978- If your car has Starlink, make sure you yank the DCM fuse or remove the system…. In my 2017 Outback 3.6R, the Starlink system is 3G based. With the 3G towers going down last year (spring of 2023) it seems to cause a big problem with Starlink trying to connect. BTW, this is even if Starlink was never used/activated, and even when the car is “off.”

@kushp4934

6 ай бұрын

​@@Teenagegoogoomuklol I'm doing the same thing. Dealer said no issue, whilst 2 batteries gone in a matter of couple months. So I just both a 30 dollar charger and now it's a ev :)

Thanks!

@DadsGarageDiagnosticSpecialist

10 ай бұрын

Thank you!

I had one where the body was dented slightly from the seat belt hanging out when they were closing the door. It was letting the door ajar switch stick open just far enough to cause the door light at the bottom of the door to light but not turn the door ajar light on the cluster. You couldn't really see the light on with the door closed either. I never looked at a wiring diagram to figure out why it wouldn't set the door ajar light but thinking back wish i had.

@DadsGarageDiagnosticSpecialist

10 ай бұрын

I've seen things like that back in the day when door ajar switches were still adjustable. The most challenging draw diagnostic I ever did was an early 90s K2500....it would go dead overnight reliably...owned by my boss at the time...I checked that thing thoroughly every time and it never had a draw or any problems in the shop. I found it parked out back facing steeply uphill.....hood switch was turning the under hood lamp on while parked in his spot only..... not really a fault with the vehicle nor something I could ever find other than thinking outside the box. We disconnected the hood light and it never had that problem again. That was the truck that taught me a lot about draw testing and starting systems, etc.. Thanks for sharing.

Went thru this with my 2019 Outback. Subaru Corp will replace the 400 amp crank to a 600 amp crank. The factory battery is to weak to store a long term charge. Tell them you replaced the battery when they ask.

@DadsGarageDiagnosticSpecialist

7 ай бұрын

That is interesting… Yeah 400 cold cranking amps is very minimal. Thanks.

I know I know ! The customers honey got in there with a key and was jamming out and left the dome light on, maybe even ran the AC fan for "fresh air", was running the window up and down.... So an occupant drained it then "shut off the dome light" to cover up the sin. GUARANTEED !

@DadsGarageDiagnosticSpecialist

10 ай бұрын

I’ve seen it over the years. Wouldn’t doubt something like that happened. Thanks.

My cousins 2108 Impreza goes dead overnight if she leaves the key in the ignition. Dont know what is doing it, but the simple workaround was to always remove the key.

@DadsGarageDiagnosticSpecialist

10 күн бұрын

Thanks for sharing.

Just wondering if the customer is charged for the time you spent due to the bad reading the meter gave you, or does the labour get adjusted. I know some shops have a flat rate, just curious. Must be frustrating for you when that happens, I know it would be for me. Again, nice behind the scenes video 👍

@DadsGarageDiagnosticSpecialist

10 ай бұрын

Did not lose much time from the tool reading incorrectly. The customer was charged the appropriate diagnostic fee. All diagnostics were completed within the allotted time so there was no need to charge more than the initial diagnostic fee. Thanks again for commenting.

This video confirms Subaru has a problem with there charging system, battery, and/or a discharge in the electrical system. Why don’t they fix it?

@DadsGarageDiagnosticSpecialist

5 ай бұрын

I am not sure. I guess I don’t see enough of them anymore. Thanks for commenting.

New parts don’t always me good working parts

@DadsGarageDiagnosticSpecialist

10 ай бұрын

Thats right. I've gotten a lot of new parts that were faulty right out of the box. I have also seen plenty of new batteries that were faulty also. Thanks for commenting again.

inductive amp clamps will pickup earths magnetic field.

@DadsGarageDiagnosticSpecialist

10 ай бұрын

It picks up the fluorescent lights in the shop really bad too. Thanks for sharing.

How about door locks being misaligned

@DadsGarageDiagnosticSpecialist

10 ай бұрын

That is definitely a possibility. Have not had any further problems with the car though so its hard to say if there ever was a problem with the car or if it was something the vehicle owner did by accident. We may never know, I didn't get the whole story. Thank you.