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I fixed a parasitic drain on my car in 408 days

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Re: I fixed a parasitic drain on my car in 408 days

#291

Post by c4mpute »

winrid wrote: post #240
mattbrewsbytes wrote: post #176

Earlier quoted context omitted.

Imagine as a software developer you tracked your time working tickets, your pay was hourly, and depending on the ticket type you were prescribed how long that ticket should take and paid those set hours whether you went over/under the set hours. This sounds completely insane but this is how car mechanics work (as I understand a lot of shops do this). Replacing a battery might be 1/4 hour labor, replacing brakes on ca…

That's kind of how dealer mechanics work but not any other mechanic... They work for 10 hours, you get billed for 10 hours.

> That's kind of how dealer mechanics work

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.

Re: I fixed a parasitic drain on my car in 408 days

#292

Post by tempestn »

somat wrote: post #184
JohnFen wrote: post #167

Earlier quoted context omitted.

I wonder if installing a switch to disconnect the car's battery entirely would be an acceptable (but obviously hacky) solution.

Not really, When powered down(battery diconnected) the computer then has to re learn parameters/pass internal validity checks. On a well preforming system this will be done in as little 1 or 2 rides but on a marginal system this can take many rides. the computer may not enter closed loop mode until these checks pass. closed loop mode is where the computer set it's output values(fuel air ratio, timing etc) based on it…

Not to mention more minor annoyances like losing radio stations and other settings.

Re: I fixed a parasitic drain on my car in 408 days

#293

Post by TheSpiceIsLife »

lylejantzi3rd wrote: post #28
overthrow wrote: post #3

Well this is timely. I have a parasitic draw on my NC Miata. The first mechanic just replaced the battery. The second told me it's normal for the battery to die if you don't drive it for 3 days (because "cars have computers now"). It seems like mechanics really don't like digging into the electrical part of the car... but these days that encompasses more and more of what can go wrong. Without time to dig into it myse…

> It seems like mechanics really don't like digging into the electrical part of the car... 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.…

Have you consulted an auto electrician?

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.

Re: I fixed a parasitic drain on my car in 408 days

#294

Post by Dalewyn »

civilized wrote: post #166

My wife and I gave our old car to her parents. In the subsequent years, its battery kept dying and we had to go over to their place and jump it. Never happened in the prior 7 years we'd owned the car. The mechanic said nothing wrong with the battery, but suggested there might be a parasitic drain somewhere. A few days later, we were visiting them. I looked at the car and saw the door closed, but not properly latched…

Tangent, but what's the rationale for car doors requiring slams? They are the only door I know, at least in common, daily life contexts, that require slamming them with the force of Thor to properly close them.

Re: I fixed a parasitic drain on my car in 408 days

#296

Post by aksss »

kccqzy wrote: post #7
overthrow wrote: post #3

Well this is timely. I have a parasitic draw on my NC Miata. The first mechanic just replaced the battery. The second told me it's normal for the battery to die if you don't drive it for 3 days (because "cars have computers now"). It seems like mechanics really don't like digging into the electrical part of the car... but these days that encompasses more and more of what can go wrong. Without time to dig into it myse…

> it's normal for the battery to die if you don't drive it for 3 days 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?

Table for reference: https://homebatterybank.com/how-fast-will-a-car-battery-drai...

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.

Re: I fixed a parasitic drain on my car in 408 days

#297

Post by bhauer »

markdoubleyou wrote: post #44
overthrow wrote: post #3

Well this is timely. I have a parasitic draw on my NC Miata. The first mechanic just replaced the battery. The second told me it's normal for the battery to die if you don't drive it for 3 days (because "cars have computers now"). It seems like mechanics really don't like digging into the electrical part of the car... but these days that encompasses more and more of what can go wrong. Without time to dig into it myse…

My last car, a 2007 Acura TSX, had the same problem--it wouldn't start after 4 or 5 days (maybe 2 or 3 during the winter). This model was from the first wave of touchscreens and bluetooth. Mechanics shrugged, pointed to the tiny, underpowered battery, and told me to drive it more. Thankfully there are a lot of car enthusiast forums out there that have been plugging away on vBulletin for years. Someone on an Acura for…

Same problem with our 2007 Acura TL. And we fixed it the same way.

Re: I fixed a parasitic drain on my car in 408 days

#298

Post by aksss »

markdoubleyou wrote: post #44
overthrow wrote: post #3

Well this is timely. I have a parasitic draw on my NC Miata. The first mechanic just replaced the battery. The second told me it's normal for the battery to die if you don't drive it for 3 days (because "cars have computers now"). It seems like mechanics really don't like digging into the electrical part of the car... but these days that encompasses more and more of what can go wrong. Without time to dig into it myse…

My last car, a 2007 Acura TSX, had the same problem--it wouldn't start after 4 or 5 days (maybe 2 or 3 during the winter). This model was from the first wave of touchscreens and bluetooth. Mechanics shrugged, pointed to the tiny, underpowered battery, and told me to drive it more. Thankfully there are a lot of car enthusiast forums out there that have been plugging away on vBulletin for years. Someone on an Acura for…

God bless online car forums. Usually just awesome, well-intentioned, and helpful people that participate, with decades of knowledge indexed. There was a year way back there when the usefulness of the forums surpassed the Chilton's manual for me entirely - probably something to do with the addition of YouTube.

Re: I fixed a parasitic drain on my car in 408 days

#299

Post by rrmm »

mbfg wrote: post #82

South Main Auto has an excellent youtube channel with various parasitic draw videos. For those struggling, it's a good watch. Here's one such: https://www.youtube.com/watch?v=qDqlG5bRq8k

Second this suggestion for anyone working through parasitic draw issues. He has a very solid, logical process for working through this (among other issues). I always enjoy watching the videos because it's like watching a who-dun-it where you're trying to guess the cause as he gathers evidence.

Re: I fixed a parasitic drain on my car in 408 days

#300

Post by c4mpute »

amtamt wrote: post #137
bityard wrote: post #126

Earlier quoted context omitted.

> It seems like mechanics really don't like digging into the electrical part of the car. 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…

This sounds like a majority of software engineers (and their direct managers) asking to add more CPU and RAM, when software is slow, instead of analysing a problem. I guess mechanic's time is more valuable than parts.

I'd phrase it like: parts have a higher profit margin...
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