Wield marks on battery (weird error codes)

[Audun]

Originally Posted by MightyMouseTech

Modern battery testers don't actually put a load on the battery, they measure the capacitance of the battery. If it is at 95% health, you are good to go.

Most important thing is that ground strap. When it gets corroded, all sorts of issues happen. Computer faults, electric power steering faults, misfires, and when really bad the car won't start.

You can look on realoem.com and it will help show where the cable is. Not sure what side of the car it will be on an EU car. On a North American car, it will be very close to the ground, underneath the steering shaft a little before it connects to the steering rack.

Thanks man! You guys are full of knowledge. Or just really cool bimmer nerds;P
There's nothing like people with EXPERIENCE passing it on.

It's greatly appreciated.

[Audun]

Cleaned it up today (Will locate and do the wiring under the car later, both red and brown/black) It's a hazzle lying under there and getting the plastic cover off :P
-Cleaned the metal parts with 12% white vinegar (found this under weed killer in an autostore) You could see it bubbling as I submerged them.
-Brushed everything with #0000 finegrit steel wool and a steel brush
-Put Isopropanol on everything (It evaporates quickly and gets remaining gunk)
-Smeared battery pole grease on everything (I assume this is dielectric grease)

Mounted together.

I highly recommend everyone with an electronic system car to do this. It's a coincidence this happened to me on the very first BMW car purchase. It seems the car has been running well as long as it was relatively hot. But when I took it home, the weather changed drastically overnight. It seems why this all started, taken your comments, BMW shop on the phone, and others you all mentioned this.
Need to check under the car to address all weak points, but I recon it's this.

Will post pics later from under the car and see how it looks.

I'm now glad all this happened or else I would never have learned. And thank you so much for your insight, it's your comments that made me do this.

[JimD]

You could tell a couple things from your voltage measurements. A fully charged battery should read about 13V with no load. Yours was less indicating it was partially discharged (or working through resistance from corroded connections). With the engine running you had almost 15V. The battery cannot produce that so the alternator was working. If the voltage is above 13.2 with the engine running the alternator is working.

In the U. S. you can buy a cheap meter which does these measurements but just displays the result as green/yellow/red and also has a large resister to do a load measurement on the battery for about $20 from harbor freight. You can only engage the resister for a few seconds but it draws about 100A from the battery. Again you read the voltage illustrated as green/yellow or red. It's crude but gives useful information.

[NorthernDancer]

Auden: thanks for feedback and good pics. I always say electrical issues are 85% caused by loose and/or dirty connections.

[Audun]

Thanks for posts.

Checked the ground where I could find it in the front. Didn't look good, and didn't want to bother laying under the car fixing this. So I took it to BMW. (smart)

They said the red plus pole wire all the way from the battery post to the front of the engine was irrated? (verdigris, corroded copper)
How they can see that on an isolated wire I don't know.


Workshop costs: 2hrs diagnostics with spark plugs 470£

They gave a quote on:
To change the red wire all the way 1200£

Price for only red wire 276£

I have to pay for the diagnostics but I'm NOT paying for anything else. I'm not paying another person to change a 2.5m wire for 1200£!!!! It's insane. I'm shocked as I said to them.
"-They COULD make a transition at the back of the car and just do the short battery red wire piece, but that would be an 'out of the door' type of guarantee, and might lasts years but it's no guarantee."


They said the brown ground wire at the front (picture) wasn't a problem. (I'm concerned that they don't even mention what it can do in the long run, as if it's no big deal. It doesn't look good)

They said they came up with a temporarily solution so they didn't
have to push the car back and forth from the shop to the outside
(don't know what that solution is, and why it works if the whole wire is corroded) He didn't know, the mechanic knew.

None of the shops have mentioned what the CAUSE of all this is. But judging on everything it seems that the previous owner has jumper cable helped someone else or himself and put everything in the wrong place frying the plus pole(as in the pictures)
And this has given a current enough to affect the copper inside the plus wire.
Or what? Have no idea. Then a fuse should've gone. No one has mentioned fuses at all. I ASSUME the mechanics have checked that and excluded it.

With road help, first shop and 2nd shop I'm at a total price of 1110£ (For spark plugs pretty much)

At least I now know what it is.
Couldn't find this red plus wire on oemparts. I would rather have a cheaper part also. I can see the short one around the battery, but not the long one that goes from the back to the front.

Have any of you changed this red wire before? Is it hard to change it? Would there be a way to stop the corrosion and renew the wire? Cut it open and 'treat' the copper. And re-isolate the wire. I don't know....

What I've struggled with more is get the car elevated properly. Thinking of making wood boxed to get it off the ground.

[Audun]

Refurbished cable. It was completely torn off. But seems like this was the weak spot. Didn't say anything about the other side. This was a temporarily solution from bmw. The original cable vendors say are 4 meters. My god what a stretch.

How can the ends of this cable be exposed to water? What happens if water hits them?

Wonder if there's a cable like this that is a better construction. Especially at the ends.