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I fixed a parasitic drain on my car in 408 days

davidmuller.github.io

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

#232

Earlier quoted context omitted.

I hear this all the time, but I have never understood it. If I clear my drive cycle monitors, they are all passing again just a few miles later. Do some vehicle manufacturers just put insane constraints on the drive cycle monitors?

> Do some vehicle manufacturers just put insane constraints on the drive cycle monitors? Yes. Combine with the fact some only pass after certain conditions (eg. over 3000 revs for 10 mins, or idle for 5 mins, or only after 3 starts, only when the outdoor temperature is within this range, etc). Sometimes those conditions aren't stated in the manuals. That makes the checks passing seem more like a random process and dr…

And some jurisdictions will pass some “not ready” codes because a proper cycle may not happen for months.

A code reader really pays off sometimes to reset everything :)

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

#233
post #149

In the 00s, my dad had an issue with the infotainment system of its Peugeot 407 that would no longer boot. An official Peugeot mechanic told him that it would cost something like 4200€ to replace the unit, so he asked me if I could have a look. After a quick search, I found an update for his system, burn it on a CD, and put the CD into its car. The system updated, and then would work normally. Problem fixed for one h…

A lot of dealership mechanics are mindless flowchart followers that aren’t even allowed to use their brain.

Though I’m surprised “update” wasn’t a part of that official flowchart.

Have had dealership mechanics ignore my notes and identify a part as being failed despite my method of 100% excluding that part as being bad.

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

#234

Thanks for this timely post. I'm literally in the middle of running down a parasitic drain on my Nissan Xterra. I tracked mine down using a different method which helps when your fuses don't all have test points (and no conversion table needed). - Disconnect negative battery cable - Switch your multimeter to 10A (don't forget to swap lead ports) - Connect the multimeter in-line between the negative cable and negative…

And pro-tip if you need to go down the line past the fuse box: if you have a DC clamp-on ammeter, you can do multiple windings to 2x or 3x the current readings for smaller draws that the clamp-on might not pick up on.

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

#235

Not just for highly computerized cars, I have a 97 Ranger where literally everything is manual and I don't even have a dome light anymore. There's a parasitic drain I can't quite figure out so I just make sure to start it every once in a while. Since I'm a year round bike commuter the truck can sit around for a long time, especially in winter when there's no house and garden projects. I've considered adding a manual…

Solar panel? Depends how big the draw is.

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

#236
post #7

Earlier quoted context omitted.

> 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?

My wife drives about once a week, probably less on average. She has a 2013 Honda CR-V, only 15,000 miles on it. We live in Minnesota, so have cold temps, but the car in a garage. The car always starts. We've replaced the battery once just due to longevity. Every 3 days? No way.

15k miles on a 2013 CR-V? Enjoy the last car you'll ever own! I assume you know this, but some of the maintenance items for that car are 8 years I think; worth checking the manual to find out!

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

#237

Once you find the fuse that passes the highest current, why not just place a switch button in series with it? Turn it off when exiting the car. Add an LED to show when it is on.

If you’re going to do all that, just rewire it so the circuit only turns on with key-on.

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

#238

Earlier quoted context omitted.

I hear people say that about my BMW, and realistically the hassle of some reliability issues is nothing compared to driving the lifeless husks of cars they recommend instead. (there are reliable sports cars, but it significantly limits the pool you can select from)

That's fair, but it's funny because that's how I always felt about BMWs. My buddy loves them but I always felt like they were so... sterile. Unless you are at a track or love cutting off people in traffic it feels really hard to have any fun in one.

> My buddy loves them but I always felt like they were so... sterile.

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?

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

#239

I found that my old (1997) Range Rover would flatten its battery after being parked outside my house over a weekend. If I didn't drive it for two or three days, it would be too flat to start. It turns out that the BECM (body ECU) wakes up from sleep if it hears anything coming in from the RF keyfob receiver, on 433.92MHz, a standard ISM frequency. If it's not a valid fob code (and there is a surprisingly complex roll…

Can't recall where, but I recently learned this was a common issue at airports in the early days of wireless key fobs. The radar sweep at the airport would wake up the receivers causing cars parked there for a while to have dead batteries.

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

#240

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…

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.
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