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Discussion Starter · #1 ·
I have been searching high and low and have seen a number of references to this kit but can't find it at the dealership's parts web site or any of the regular sites I search.

Anyone know where I can get one of these for my 2000 M5?
 

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Discussion Starter · #3 ·
Quote from another forum...

BST is; essentially BST is an "explosive" connection which gets triggered during collision which disconnects the cable that runs to the starter. Explosion obviously cannot be heard nor felt, but you can see from below pictures that explosion is definitely present. I tried finding an answer to "how much force actually triggers the explosion", but couldn't find it anywhere. I was rear ended on the highway back in October (by a 535...), my airbags were not triggered, the seat belt tensioned, the car shut off and hazards went on. When I tried starting the car, it wouldn't start so I had to get it towed off the highway. A little search on e46fanatics, screw driver and some duct tape got my car started again... I basically opened up the plastic housing that covers the connection, inserted male and female ends into each other taped it up and drove around like that before my car was fixed at the shop. The body shop never replaced the BST, even though we had discussed it when I dropped the car off; however after I picked up my car and realized they never replaced it, we agreed that they will provide the cable and I will put it in myself – the part itself is over $500…
 

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This is difficult to find.

Try part no. 1 here:
RealOEM.com   BMW E39 M5 Battery cable

I've heard that BMW make a repair kit where you cuv the original battery cable and join in a new section from the battery for a couple of feet or so; this would avoid having to tear out half the car to refit a new positive cable all along the car.

However, I've never seen the part number for this repair kit for the M5.

I've had a look under an M3 as well, but it doesn't show a repair kit either (different shaped terminal anyway-so no good really, I was hoping for a 'route' to the battery repair cables on realoem). I think I've seen a repair kit for an ordinary e46 but couldn't spot it now.

Failing that, a new positive battery cable from the boot (trunk) to the starter is the only 'correct' way to go.

I hope this helps but does mean a lot of work.
 

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Discussion Starter · #5 ·
Thanks ger. It looks like your search came up the same as mine. I appreciate your response.
 

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Try to find out some good bmw repair kit for that one, or at least, some good shops and stores that can compensate all your needs. In that way, things would have been very much good and will be able to make your vehicle repaired, most especially it is the battery.
 

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Good finds.

Do bear in mind the price for both. Repair cable is $381 and the actual full length M5 positive cable is $402 (I linked to it higher up).

I also wonder how long is the 540 repair cable, as the battery is in a different position compared to the M5 and it might require a longer cable. Also, it would be wise to confirm that the battery terminals are the same shape, they could easily differ due to the different battery locations. I know the M5 terminal is low, flat and sticks out forwards a few inches; I haven't seen a 540 (or other version) terminal, especially with this in mind, but I have a feeling they are different. Could someone confirm this? However, the repair could be completed in the boot/trunk.

Using a new M5 cable would require removing the rear seat, possibly front seat and also the carpet on the right hand side. I believe the cable runs from the rear to the front footwell area, where it ends in a relatively chunky bolt connection where it goes through the floor. From this connection it continues to the starter and alternator.

Changing this cable would be very expensive if you were to pay someone for the labour. Doing it yourself would only cost time and patience and would be the way to go to get the car perfect and it would only cost $20 more than the repair cable.

Incidentally, the remainder of the car's electrical systems are fed from a seperate (and slightly lighter) positive cable, bolted to the battery terminal that feeds the fusebox in the boot and, through a fuse, itself continues to the front of the car along a similar route to the starter/alternator cable, though it doesnt go through the floor. Anyone who's stripped a car down could elaborate a bit more regarding its route etc.
The whole idea of the BST (Battery Safety Terminal-with the explosive airbag type charge) is for the engine to be disconnected (in an accident) but the other systems still available.
 

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idk if its available for the m5 but i replaced one of these on an e46. it came as the bst/sbk with a length of cable attatched and a compression type fitting/connector. you cut the original cable and then use the connector provided to attatch the new bst.
 

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Discussion Starter · #13 ·
I found a used cable (complete) on the Parts For Sale and Wanted forum here. I have not had a chance to replace the old one yet, but it seems to be a pretty straight forward exercise.
 

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Resurrecting an old threat. This issue has been occurring since I purchased my M5, and I thought I had fixed it, but I was wrong.

I would regularly drive somewhere, shut off the car, then come back and it was completely dead. I thought the battery was crap and really old, so I replaced the battery and the issue continued. I then used a wire brush to clean the terminals on the battery, cleaned the connectors, used some dielectric grease, tightened it up and the issue went away for a whole 2 drives. Came back.

It happened again last night, I'd been driving the car all week without an issue. Park and get some ice cream with my lady, and boom, car is dead again. I go to the trunk, fidget the cables and the car starts without any hesitation. It's getting extremely frustrating having to do this.

If I'm understanding this thread, can I buy new connectors, hack off the ones in the trunk, and solder/heat shrink new connectors?
 

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Sorry to bring this back up, but I installed some battery post shims, and that seems to have done the trick regarding any loose terminal connections.

Cleaned the battery posts > applied dielectric grease > installed shims > applied more grease > fitted the terminals nice and snug.

If i'm being honest here, I had a battery in the car that kept dying, and I thought needed to be replaced even though the date of manufacture was September 2017 and I feel very stupid. I wasted $200.00 on a new battery a few months back after I got fed up the 10th time I had to fidget the cables around.

$2.50 later, I've started the car about 30x without any issues finally.

Learn from my silly mistakes. :)
 
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I would guess you might not have even needed the shims. I had the exact same problem and simply needed to clean my terminals and the connectors. Problem solved. Now I have an extra battery cable and ground cable in my garage...

Doug
 

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I'm not trying to sound rude, but do you really think I didn't try that first? I cleaned the terminals, applied some dielectric grease, but the connector was always loose no matter how much I tightened it. It would slip right off with only the slight pulling of your index finger.
 

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I'm not trying to sound rude, but do you really think I didn't try that first? I cleaned the terminals, applied some dielectric grease, but the connector was always loose no matter how much I tightened it. It would slip right off with only the slight pulling of your index finger.
I don't know, but you seem to think it is normal to have the wrong size terminals on your battery (which is the only reason to use shims, and is the only way shims would have fit on in the first place), so yeah, it guess it seems logical to me that you might not have tried cleaning them.

Glad you got it resolved.

d-
 
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