Positive Battery Terminal Wire

[Phoenix319]

I have no idea what this wire is or what it does but it broke off the positive cable and I want to replace it. Anyone know anything about it? It's the highlighted wire in this picture and it leads back to this white splitter.

[Phoenix319]

Is it Aftermarket? Does no one know what this is?

[DesktopDave]

Looks like someone added it. BMW doesn't tend to use slotted screws or washers like that on the battery terminal. I'm not sure what the heck is going on there but I've never seen anything like it on my BMWs. Where does the black/red (red/black?) wire coming out of it go? Under the fuse box? If I had to guess, I'd think someone added a wire for an aftermarket stereo or amp. The white cover might be an aftermarket inline fuse holder.

[Phoenix319]

It it connects to the same place the braided ground strap on the negative terminal connects. Probably something the previous owner did. My stereo, OBC, Trunk Light, and interior lights no longer work but I'm not sure if that's from changing the battery or if it's from this wire.

[Sansouci]

Why would a lead from the pos terminal connect to the same place as a neg ground strap. Look up the ETM wiring diagram in the tech section to verify it was OEM, but not likely from others' comments. Then retrace the wiring for your non-working components in the ETM. It may have neen used as a bypass or jumper for corroded leads given some evidence in your picture.
Happy Hunting.

[Derekwh]

I had a similar set up that ran back to a "mobile" phone setup that was mounted under a rear seat. I lightened the car by about 20 pounds removing the phone and CD changer and all the wiring. Looks cleaner too.

[Phoenix319]

Well I'm going to have a fun time reading the wiring diagram and replacing a couple cables. Both of my battery cables are rusted and the negative one is corroded. Thank you for the help again guys!

[schuy61]

Well I'm going to have a fun time reading the wiring diagram and replacing a couple cables. Both of my battery cables are rusted and the negative one is corroded. Thank you for the help again guys!

Hi, new to the forum . Am finishing up a ground up resto on my 77 BMW E24 630 CSi.
Just happen to be at the battery hookup stage( only been 5 years in the process).
OK. I believe mine originally had a pos cable with a smaller diameter, short "leg" on it that went into (underneath) that large lump of fuses and relays( clear plastic cover). The longer red cable section went to the starter solenoid on top of starter.
Original cable trashed, ordered new one years ago. As I said, I'm on it today and find that my NEW one from BMW doesn't look at all like my original to this memory. Has the short leg but the remaining section is way too short to reach the starter and the end has some funky connector/clamp with a bolt attached. It DOES however match the drawing for same from Real OEM website. Only other pos cables I find aftermarket are either simple red long cable with or without the leg.
I'm stumped at this point too. I can add that ;according, to my BMW shop manual wiring diagrams there is a "separate" or additional wiring diagram for the 6 series. It does differ in the battery area from the overall or master diagram in the manual. Still working on it. I suspect maybe a typo ??
I'm looking to replace my new one with a correct one if I can find it ! I'm a purist and only restore to original.
pete

[schuy61]

Hi, new to the forum . Am finishing up a ground up resto on my 77 BMW E24 630 CSi.
Just happen to be at the battery hookup stage( only been 5 years in the process).
OK. I believe mine originally had a pos cable with a smaller diameter, short "leg" on it that went into (underneath) that large lump of fuses and relays( clear plastic cover). The longer red cable section went to the starter solenoid on top of starter.
Original cable trashed, ordered new one years ago. As I said, I'm on it today and find that my NEW one from BMW doesn't look at all like my original to this memory. Has the short leg but the remaining section is way too short to reach the starter and the end has some funky connector/clamp with a bolt attached. It DOES however match the drawing for same from Real OEM website. Only other pos cables I find aftermarket are either simple red long cable with or without the leg.
I'm stumped at this point too. I can add that ;according, to my BMW shop manual wiring diagrams there is a "separate" or additional wiring diagram for the 6 series. It does differ in the battery area from the overall or master diagram in the manual. Still working on it. I suspect maybe a typo ??
I'm looking to replace my new one with a correct one if I can find it ! I'm a purist and only restore to original.
pete

Did a bit more on this. See above. I think the new NOS BMW cable I spoke of is correct for your 85 but not at all correct for my 77. Want my new one, cheap? For your 85 case this one has the "leg" or pigtail that goes into/underneath the fuse/relay box as I said and I believe the other funky end connects to some sort of splitter somewhere (as someone suggested) separate from the battery pos post. I.e. I think the battery pos post should have only have the cable end clamp on it. My guess is that one of the wires you show at the post must go to the starter (they bypassed the splitter). You need to trace back the others at the post to where/what they connect to.
The white covered bit in second pic might well be a add on? or not, fuse or protector for some other appliance.
FYI, its HOT, disconnect cable before working, please
My shop manual is for a 1977 so I'm limited in my thinking to what the 77 wiring diagrams show. NO splitter that I can find. Finally it's clear to me now that MY 77 correct pos cable has the pigtail and then about 30 inches of cable directly to the starter.
pete

[RSheiman]

You have an aftermarket alarm system?