Without time to dig into it myself I've just been parking it with a battery tender every time I come home.
Tell me about it. I'm in a similar boat. My audi a4 has had a parasitic draw for the past 10 years. My mechanic didn't want to take the time to address it because that sort of thing takes a serious amount of time and he's always backed up. I got out my fluke and narrowed the cause to what I believe is the comfort control unit. I can't replace it myself because it's a coded part. My mechanic won't do it because he won't confirm that's the cause.
None of the other mechanics in my area have the equipment. Even the Audi dealership won't touch it because they're backed up too. So, I keep a battery jumper in the glove box and hook the battery up to a tender when I can (outdoor parking).
I don't know what I'm going to do for my next car. Pretty much every car made after 2010 has coded parts and are more computer than mechanical. It does make me tempted to learn the electronics part and open a garage that focuses specifically on fixing electronic issues in modern cars.
(there are reliable sports cars, but it significantly limits the pool you can select from)
(I'm talking about pre-2010 BMW here; I would totally agree with most new ones being sterile)
BMW really ramped up the electronic complication starting with my E83, and that shit wears out right alongside all the typical flimsy BMW plastics and rubbers. Plus the delightful parasitic drains from tfa.
They also ramped up their maintenance-unfriendly designs around the E46 era. On an E39, a rear spring swap is easy. Try it on a newer one, and you will regret the attempt.
(Although the Mazdaspeed6 was 90% of a BMW with 10% of the maintenance bill).
I'd love to know which specific model you found sterile (wouldn't happen to be some 4 cylinder would it?)
People who drive boring cars love to parrot magazine reviewers... not realizing their definition of sterile is relative to a 911, not their Accord.
> Unless you are at a track or love cutting off people in traffic it feels really hard to have any fun in one.
I track my cars, but it's not hard to enjoy pleasant driving dynamics without resorting to being an irresponsible driver in a well-sorted car.
I'll defer to you on how fun cutting people off in traffic is though?
The Audi was great fun to drive though, no denying that. Just different priorities in what I want out of a car.
How many hours of shop time are you willing to pay for with no guarantee of a solution, and very few (if any) parts replaced?
Most people will give up, stop researching and buy a new car when the dealer tells them it can't be fixed.
Shoutout to "The Hondew Shop" in Dallas. He does great work on all Honda/Acura products!
He had the people at the dealership drive the car. They acknowledged the problem and got on a call together with Ford. Ford refused to even entertain the idea there was a flaw but less than a year later they came up with a "software patch".
Pete would bring it up with anyone he met. Do not buy a Ford Focus / Ford Fiesta with automatic transmission.
Imagine opening a computer software support business where you bring in your old proprietary binary programs that you got from who knows where, and the business is to fix bugs you've found.
Maybe some really big enterprises would pay for that sort of thing. But I doubt it would be feasible for consumer stuff.
It would be a crazy/fun kind of business to run. I'm sure it probably exists.
Bug Hunters
Extremely valuable service. I bet there'd be a lot of demand.
Having had a 2006 model car in my workshop forever rebuilding the engine, I have though it might be worthwhile starting a business doing that kind of trouble shooting but nobody will want to pay, because the vehicles involved are inevitably old and worthless. It's fun to do it for yourself, but as a business your typical customer who needs you won't be able to justify paying you.
My other thought was to possibly set up the tools and whatnot to support local businesses in doing that kind of troubleshooting on older cars but building the knowledge and tools to distribute would be a very expensive exercise.
I love this phrase, and it reminds me that the behavior exists in the computer world too. From the Jargon File:
field circus: [a derogatory pun on `field service'] n. The field service organization of any hardware manufacturer, but especially DEC. There is an entire genre of jokes about DEC field circus engineers:
Q: How can you recognize a DEC field circus engineer with a flat tire?
A: He's changing one tire at a time to see which one is flat.
Q: How can you recognize a DEC field circus engineer who is out of gas?
A: He's changing one tire at a time to see which one is flat.
Then there were the cases with arbitrary random bluescreens that were impossible to diagnose where I'd upfront tell them I could only do the bare minimum because otherwise they might have to pay 500 Euros for a solution that probably wouldn't work.
You might have to reprogram your radio channels...
His strategy isn't to pull fuses, it's to set the car sit for at least 30 minutes or so (with key off) and then check each fuse with a multimeter to see which has current on it, and then check everything on that circuit. Arm yourself with schematics and wiring diagrams, otherwise it'll end up being something of a wild goose chase.
(The idea being if you start pulling fuses, you can "reset" various computers in the car, which may show up as a false positive. It can take up to 30 minutes or so for all the various computers in a car to all go to sleep, although it's usually only a few minutes for most cars.)
I'm sure there was a more elegant solution (find a different fuse, rig up a button, etc.) but this was the path of least resistance and wasn't really annoying to do.
https://i.pinimg.com/originals/a4/c5/bb/a4c5bbd867b819a687ea...
I avoid very new cars like the plague though, so not sure how different they are.
It makes me anxious thinking about all the bullshit in new cars - touch screens, coded parts, 4G connections with GPS tracking, etc etc.
Completely disconnect battery when not in use.
And honestly on something that used it might be the best, taking it apart again just to replace the thing you thought you might not need to is PITA
Tho a bunch of that might be because I bought "sporty car" and those rarely have easy life in the first place...
The only computer in the diesel one is the glow plug timer and there is no computer in the carbureted one (both 1991 Nissan Patrols).
The injected one is a 2005 ford falcon and is starting to get all sorts of interior electrical niggles. Only wiring issues in the patrols is a left headlight short which was easily routed around using relays.
My experience is that a lot of independent mechanics will do what you ask them to do, so long as they think it’s not unsafe and have confidence that you’ll pay the bill without complaint when the task is done whether or not the problem is fixed.
Probably not a good “this is my first time meeting you, but please replace my flux capacitor” but if you’ve got a history with the shop, I’m surprised you couldn’t talk him into it. (I worked in a shop briefly in college. We’d do what the customer wanted, including installing parts they bought, but the only warranty was on a “we spent an hour; you paid for an hour; thus ends the transaction” basis.)
Finally, the service manager agreed to check it out with the understanding that if I was wrong, I still had to pay for the time they spent investigating.
I was right :-)
Bought my own solenoid online and surprise the bike started working again.
I once moved into a place that was great, except the shower would start out hot, quickly drop to warm, and then stay warm for as long as we cared to try it. I hated this, so every time I showered I'd spend some time trying to debug it, despite knowing nothing about plumbing.
Eventually I asked myself: why do normal hot water heaters work the other way, where they stay hot a long time and then get pretty cold? Clearly, there's some way of keeping the incoming cold water separate from the already-heated hot water, like by putting the output pipe at the top and the input pipe at the bottom. But if you reverse them, you might get what we had.
I leapt out of the shower and felt the hot water heater pipes and sure enough, reversed. My landlord came over shortly thereafter and fixed it, and I felt very smug when I had my first properly hot shower.
Turned out the installer had failed to put in the high altitude kit which told it to expect a smaller pressure differential. Mostly it was fine, but on rainy days with low barometric pressure, the difference would drop below threshold. But I had to be home for enough rainy days to figure it out.
That's a great quote. I think I'll use that instead of "where there's smoke ..." from now on.
Once I got them to replace my gearbox oil even though they said it wasn't needed. With another one I brought them a third-party pedal and asked them to install it. In both cases it did solve my issue by the way, even though I might have been wrong.
They don't care as long as you're ok to pay for the hours regardless of whether it solves your problem or not.
Getting an appointment at my Audi dealer is always 6+ week minimum wait. I don't think I've ever dealt with a dealer this consistently backed up. And my issues have been recalls and brake problems; but simple oil change is a similar wait time.
Assure to write somewhere your radio code password first.
closed loop mode is where the computer set it's output values(fuel air ratio, timing etc) based on it's input sensors. open loop mode is where it sets it's outputs on known safe working values, but it may not run particularly well. i think this is related to the so called "limp mode"
Note My knowledge on this subject is very out of date. I had to figure it out for my old 2001 car. Newer vehicles may actually have flash storage and the computer parameters survive power out.
The point is all cars have a wonderful battery backup system, and resetting the computer when power is lost is also a nice feature.
the actual problem was sort of electronic-releated - leave lights on, drain battery to zero.
I put on a battery-cutout-monitor-thing. If battery drained to x%, it would disconnect the battery. to start the car, I think you had to stand on the brake pedal (add a load - like brake lights?) and it would reset and reconnect the battery - then you could start it.
(edit: should also say, I think a VIN mismatch would cause the ECU to refuse to work with that part and shut down)
Lost one key? Bummer. Lost all your keys? $2500, several hours of reprogramming time at the dealer, and a bunch of new parts shipped over from Trollhattan.
Thankfully the hacking scene has managed to bypass lots of this as Saab no longer exists to make parts. But this was the state of the art in 2003. I’m sure it’s even worse now.
That will be quite hard to overcome.
The dealership model has really been awful for legacy manufacturers.
I wonder if the Tesla mechanics are measurably better than the franchise dealers? I doubt it. I bet they have fancy testers, but when the tester is not showing 100% the right answer I doubt they are any use at all.
Service has also been way better for me than when I had cars serviced by franchised dealers, but that may be because I'm in SF. I had an issue and two days later a mobile Tesla service car came to my house and fixed it in my driveway for free.
>Service has also been way better for me than when I had cars serviced by franchised dealers
Which franchised electric car dealer are you comparing it to?
Can you please explain this? Why does it need ‘coding’? It’s not a VIN specific part I’d think - i.e. engine controller. Also have you explored Ross Tech VCDS tool? You might be able to identify the coding on your part and use it on a new part. Replacing an ecu should be straightforward imo.
Really? I would have thought that'd be one of the most complicated things to replace.
For other modules they're often used across many different cars/engine/transmission/body type and regulatory markets. "Coding" a module tells it what accessories/options it's connected to, what else is in the car, what regulatory market it is in, and so on.
There's also "coding" for how the module behaves with certain features. For example, body control modules on US cars won't allow you to use the remote to roll up the windows, but by flipping one of the coding bits, you can enable it. There's also silly stuff like enabling / disabling gauge sweep on the dash.
(Explaining this mostly for others, you seem aware of at least some of this)
In Australia Automotive Electronician is a trade itself.
A good mechanic should be able to point you to their preferred auto electrical workshop when they suspect an issue is outside their own scope.
It's with the price just to see the looks on the faces of stranded motorists you help jump start in one or two minutes after they've been trying for an hour to jumpstart a minivan with a hatchback.
After a short and inconclusive session looking for leaks through the fuse box, and then many, many hours of crawling around under the truck with a voltmeter, I discovered a frayed and heavily corroded +12v lead associated with the tow harness rubbing against the chassis. Fixed it. Issue resolved.
Unfortunately, a majority of mechanics simply aren’t competent, and the remainder don’t want to touch jobs which are mysteries, as they’ll just end up with a customer refusing to pay.
If you've ever seen a car's complete wiring harness you'll know why. It's not only because there's three gazillions of wires - they're also heavily insulated with tape that makes it a nightmare to access those wires in the first place.
My old math teacher would deduct points for not listing the units.
But I've heard so many stories of friends paying hundreds to auto sparkies only for the problem to remain.
I've heard this nonsense a couple times now. I was incredulous at first but everyone seems to say this. What are anyone's suggestions for a weekend-only car? (I bike to work so I don't need a car on weekdays.) Trickle charge the car battery on weekdays?
Most new-ish cars also store the dinamic engine calibration data in ECU RAM so if you disconnect the battery you can find your engine running harsher next time. So are the values of the headlights auto leveling system and other stuff.
You're also risking to reset the radio/media unit security code (on cars that aren't too new but also not super old), which if you got the car second hand and the former owner didn't save the piece of paper it came with and give it to you, tough luck unlocking it.
If you want to get fancy you can isolate the exact fuse and switch just that:
https://www.ebay.com/itm/175668177479
Thinking more, given how common parasitic drains are, carmakers should have all non-essential fuses in a separate subpanel section that can be easily switched off/diagnosed.
That's after being off for 30 minutes though. Some things stay on for a while.
If it's 'weekend only', battery should be no problem. If sometimes you leave it a couple months unused, that might be a problem.
Depending on how ready you would like to be when you're going to use it, or the access you have to your car (is it far away or in your garage?) you could add a connector for a battery charger/maintainer (some of them have accessories for plugs you can leave permanently, see the NOCO GC002 for an example), and/or add a battery switch to easily disconnect the battery.
Warning: your radio might ask for a security code if it loses battery connectivity. Be sure you have it.
My Honda HRV dies anytime it gets below -7C. Outside, inside, driven a bunch a day or two before -- once it's cold that battery taps out.
Probably a vampire drain but I suspect it's just a small battery. My old 2013 Mazda 3 starts in -25C without fail.
I agree colder weather is always a bigger issue and at 1-2 months I'd definitely be thinking of a trickle charger if at all possible. An older car I didn't drive in the winter would definitely end up with a dead battery if I didn't keep it on a charger.
They were also the original batteries used in Miata's since they give off a lot less hydrogen when charging. Since the Miata battery is in the trunk, and all lead acid batteries give off hydrogen when charging, and hydrogen in an enclosed space can also be rightfully called a bomb, having less of that is a good thing!
Did the Miata not come with a hole in the trunk floor for an exhaust hose for the battery? Both of my cars did...
Even if you’re spending $50/weekend (which is a fair amount of driving — Communauto is as low as $3/hr), that’s still quite a bit cheaper than owning a depreciating asset with lifetime maintenance costs (not to even mention insurance and fuel).
I'm jealous of the carshare options that seem to be available elsewhere. If it were as easy here as in this NJB video, it'd be a no-brainer: https://youtu.be/OObwqreAJ48
From your link. I'll let others decide whether or not that is "lying".
The average car in average condition should go around a month without being driven. Anything less than that either means a battery nearing the end of its life, not getting charged, or a parasitic draw somewhere.
Every 3 days? No way.
Good point on the maintenance. I do get the oil changed, again more by time than distance, and I'll look up the other stuff now that you've mentioned it, thanks.
That said, I'd expect most cars should be able to manage, say, 2-3 months. It's when I exceed 4 months with some regularity that battery life starts getting sketchy.
If you're driving the car every weekend, I'd expect that should be plenty. Note that fancier cars with more electronic features don't do well when only driven short distances. If you only drive 2-3 miles at a time, you might be discharging the battery faster than you're charging it.
That said, at between like 0F and -10F, I'd be intentional about starting that car every couple days. Below -10F to -20F, I'd start it each day. Below -20, I'd consider bringing the battery inside for the night - even if you have a battery blanket. Once a lead-acid car battery has frozen, it will die very quickly from then on - I'd believe within a few days or less even in normal weather. AGM batteries are awesome alternatives for the cold weather lifestyle, in terms of their resistance to freezing damage.
I have a week-end only car (2002 Mini) and I've had no issue letting sit for a week or two. Including opening/closing it without starting the engine to retrieve stuff in that timeframe.
And a week or two is on the low-end of how much you can let it sit. My SO car (1st gen citroen C3) often don't run for one or two month at a time and there is absolutely no issue with the battery.
On the other hand, if you have parasitic drain and access to an electric socket, there are battery chargers that can keep the car topped up. Or without an electric socket, just unplug the battery when the car isn't used (though that may disable some things, for example in my car the hatch is inoperable without power).
That is certainly correct. Troubleshooting electrical issues takes a different set of skills than most mechanics are trained to deal with. Most mechanics are so busy that throwing parts at a problem is the best way to deal with issues where the cause isn't readily apparent. It's not worth their time to really dig into a difficult issue because if they spend 8 hours of shop time and try to bill that to a customer, the customer is going to just balk anyway. Better to throw a part at it, bill 1.5 hrs, send it out the door, and let the next guy deal with it. And then move on to some more profitable muffler and brake repair jobs.
This is thankfully not ALL mechanics, but it certainly is a large percentage of them, IMO. (Yep, even dealerships.)
I guess mechanic's time is more valuable than parts.
It’s more common for routine maintenance to be charged by book time since it’s a standard procedure, less common for more complicated issues
Refinement: That's kind of how dealer mechanics work when they know that book time they are billing is more than the time they actually need for the task. For all the other situations, there is book time like "diagnosis, complexity high, diagnostic equipment involved" billed per 6min unit.
The horrible thing is if the car is modified, and you discover an un-fused circuit.
Weirded me out the first time I'm sitting there in silence smoking a bowl and suddenly fuel pump noises. Which were easier than normal to hear because I took the back seats (the only sound deadening in the back) out of that car so I'd have room for a full size spare tire instead.
With my current car (2020 Kia Sportage) I've noticed the head unit is waking up before I even start the car. As soon as you unlock the car I can see my flash drive light up with activity as the head unit gets ready to pickup music from where it left off.
Also, after turning the ignition on & back off there were a lot of (normal) transient draws (from things like the dome light that don't turn off immediately). Even with the problem circuit disconnected, it drew around 6A (!) immediately after the ignition was switched off, dropped to 0.4A after about a minute, and sat at that level for another 9 minutes before dropping again to 0.06A. That means if he hadn't waited ~10 minutes per test, he'd have been chasing draws that were actually normal.
Combine an intermittent fault with intermittent normal behavior, and you've got a troubleshooting nightmare.
I took it to several mechanics who couldn't find anything - because they'd unplug the battery to add a meter into the circuit. They weren't willing to wait 3 days afterwards to come back to it.
I ended up disconnecting the battery overnight. Worked fine then. Traded it in; I feel a bit bad for the next buyer.
How does this compare with the way presented in the article based on measuring resistive voltage drop across each fuse in turn?
Current passing through the resistor causes a tiny voltage drop, which is measured by the meter. As the voltage is proportional to the current, the scale painted on the cardboard behind the needle did the actual conversion.
In the author's setup the fuse takes the shunt's place; its resistance is apparently a known value that can be gathered from a datasheet.
"ye olde"? That's how every typical one works, till you go to clamp meter
> its resistance is apparently a known value that can be gathered from a datasheet.
that's... optimistic
The absolute current value probably doesn't matter - in fact I very much doubt a hobbyist-level multimeter is even capable of accurately measuring the (fractions of?) millivolts across a fuse.
It's more important as a boolean signal - "is there current being drawn on this fuse?", and then usually even those fractions of millivolts will generally be enough to make your el-cheapo multimeter register 1mV and tell you something is drawing current, where as a fuse with no voltage drop across it at all will reliably show 0mV (just like it would if the probes were shorted) on even a cheap meter.
Other method is getting DC clamp meter with low range (say 2A). Then just clamp in on wires. Bit fiddly as they work on magnetic field so they need to be reset before measure (And can work as compass in a pinch...)
I know what you're trying to say... but this reads like very dangerous advice and you may want to revise.
Ammeter between a battery's terminal and the car's electrical system.
Also note that you'll probably create sparking when doing this, and if the battery has recently been charging this can be dangerous (hydrogen outgassing).
Yah, that doesn't really make sense for small parasitic loads.
> Ammeter is not safe as general advice as a typical one won’t be anywhere near large enough capacity for working with a car battery
It should be fine with the car not "on", but the general level of danger of doing anything near a car battery requires caution.
If your multimeter has a sub-mV range -- which a decent meter should -- you can measure a voltage drop across the battery ground lead. I've successfully done that to diagnose a battery draw in my car.
It's the same principle as measuring the voltage across a fuse, except it ends up measuring the draw for the whole car, not just one circuit.
No. Not if the meter is in "Ammeter" mode (or is purely an ammeter only). An ammeter presents a very low resistance to the circuit you are attaching it to, low enough that for almost all circuits, it is effectively a "short".
If one connects an ammeter across a low resistance voltage source (i.e., across the car battery) the ammeter will appear as a short circuit to the battery, and one or more bad things will happen. The 'least bad' will be blowing a rather expensive fuse in the ammeter that protects it from this kind of accidental use. Several of the "most bad" will involve hot molten metal and/or extreme heat.
Yes. My first comment on this thread says not to do that, and suggesting an alternative is "Ammeter between a battery's terminal and the car's electrical system." instead. https://news.ycombinator.com/item?id=35514652
I was replying to "anywhere near large enough capacity" in the next post. The typical 10A range is massive overkill for typical parasitic loads in a car, and even things like the fuel pump deciding to kick on and run in most cars.
[1]This is just what I would do. Only do this based on a reputable guide if you don't have experience working around car batteries.
Thankfully there are a lot of car enthusiast forums out there that have been plugging away on vBulletin for years. Someone on an Acura forum had figured out that the bluetooth module was always on and looking for a connection. I tried disconnecting it, and the problem was fixed.
Having worked as a mechanic in my youth, and worked as a software engineer in SV, the kinds of troubleshooting skills and detail-oriented attention span involved in diagnosing these issues are far more common in the latter than the former industries.
My impression is it's rare for someone with such abilities to stay a mechanic, they can earn far more money in tech, with less exposure to hazards.
On the subject of mechanics failing to diagnose electrical issues, I have my own story too:
Decades ago, back in IL, a friend inherited a low-mileage minimalist Ford Escort hatchback, manual trans, crank windows, it was a great little econobox to inherit, on paper. He kept having the battery die on him. Not being a mechanic or even a hobbyist gearhead himself, he kept bringing it to shops. They replaced the alternator, the wiring harness, the battery, the starter, they just kept throwing parts at the car. This is what most "mechanics" do nowadays; a poorly informed process of elimination via new parts, on your dime.
I hadn't been in contact with this friend for years when I heard about this "cursed" low-mileage car sitting in his garage, full of new parts with invoices totaling well over $1k. He was car-less at the time because of this situation. I offered to fix it for him, but he didn't have any confidence left in the vehicle or my ability to fix it, he was understandably fatigued by the whole thing. So I offered something like $250 and took the car off his hands.
15 minutes with a voltmeter revealed a huge voltage drop across the negative battery terminal and the chassis. Followed the negative strap to where it attached to the chassis and the area was corroded (recall it's an IL car). Removed the rusty bolt, wire-brushed the unibody steel behind it, the bolt and cable lug, slapped dielectric grease on everything and reassembled.
The car charged the battery fine and ran like a champ. I ended up selling it back to him a year or two later for basically what I paid plus a few hundred for my trouble/towing etc. He wouldn't even take it back until I had driven it for years to prove it was fixed. It was that brutal an experience for him, dealing with "expert" "mechanics" bleeding him dry.
South Main Auto
Watch Wes Work
musty1
https://www.youtube.com/@JimmyMakingitwork
lol @ Tavarish and Samcrac mentioned here, they are TV entertainers who are more concerned about drama. If you want to learn how to repair stuff, these guys are where its at ^
Probably worth taking it to an auto electrician, rather than a mechanic.
How much of your clients' time (and therefore money) would you spend chasing down a bug in software with an unknown root cause, which never appears as long as operations schedules a restart every couple of days? Software engineers are all too happy to dive into those rabbit holes, but that's because we don't usually have to look working stiffs in the eye and hand them the bill for our services.
That's likely not an incompetent or lazy mechanic. It's an honest one who doesn't believe they can solve your problem at a price you'd accept.
The first mechanic, on the other hand, I'm a lot more suspicious of. Did they bother testing the battery before replacing it?
Mechanics don't like fishing expeditions for nonessential things. $100/h for 2+ hours diagnostic, followed by tedious parts to replace and pair up.
A new battery every couple of years and a trickle charger probably seems like better value to them.
If the battery is over 3 years old, I would replace it and start anew simply because of the life/abuse it'd had so far.
And then I'd start at the obvious ones - radio, aftermarket radio, alarm, etc. You can literally put a multimeter along the fusebox to see what is pulling voltage after - but most likely it will be something along 12V connected switch.
Wiring isn't problematic, but if you have a hitch installed it may be wired to always be on.
If anyone takes a car to a mechanic and asks for the estimate and the estimate is (100$ an hour until I find the leak and it may take a whole day or two), then most people are gonna gag.
You need to find an expert in your car.
No, this is not normal. When the cars are manufactured, they often sit for more than 3 days just to get on a train for delivery. During transport they often sit for more than 3 days.
The next time a mechanic tells you cars can't sit for a few days without a battery drain problem, ask how people who park at the airport get home after a two-week trip.
the real key to long storage (beyond a trickle charger) is clean gas.
right now, though, it only has to handle 2 weeks of sitting at most (in an attached garage).
Just need to hold a button when turning on the meter to disable the auto power of timer, then you run software on a laptop to log the data to csv
this is like saying that computer programmers don't like digging into the proprietary and binary blobs from other vendors.
I am trying to say it's not fair to blame mechanics because even if they want to dig into the electronics, the car manufacturers take active measures to prevent 'random mechanics' from digging around.
I suppose there are many rational and reasonable way to justify why this is so; probably all having some form of "because safety" and "because IP of vendors".