Electrical help please! My E24 is dead after I...

[octaneike]

Shorted the positive battery terminal to the alternator casing with a wrench when I was removing it. Yes I know what everyone is gonna say about that! 😅
I wasn't thinking. But I thought the battery was dead, it wouldn't take a charge with the trickle charger but I guess it had enough voltage to shock me and probably blow a fuse (#17) and the main relay (these according to the Electrical Troubleshooting Manual for the E24 and maybe others).

And I say probably, because the back story is that I keep it in storage connected to a trickle charger. I returned last week to find that part of the building without power, trickle chargers to both vehicles on that side were not live. Both chargers connected to a surge protector, to outlet that was dead. Actually I still need to test the surge protector to see if it did its job, or was just the outlet or line, breaker, etc. But most of that isn't visible to me, work for another day.

Anyhow after replacing the battery, had no interior lights, so didn't want to turn the key still knowing something is wrong. Disconnected batt, found fuse 17 (connected to just about all interior functions) was open, replaced that, tried again, still nothing. Disconnected battery, checked main relay and the 30A switch on it was tripped and rattling around in there. Replaced that, but with a generic one for the moment as I couldn't find the original Bosch part in stock. Still no interior lights. Pulled all fuses & relays, nothing else tripped or contacts in the distribution box appear burnt, zero damage anywhere. Removed the top portion of the power dist box, no evidence of anything underneath. No smells of burning plastic nor hint of smoke.

Some forum posts describe a fusible link in the positive cable, but I don't see one. Is it embedded? The electrical diagrams don't indicate one either, but I could have overlooked it. What else?

My car is extremely original, down to all panels, glass, and even paint. The only modification is a Alpine Bluetooth radio to in place the broken original. But wiring appears to have never been monkey'd with, also no alarm or other non-factory accessories hooked to the positive. Car ran beautifully when I parked it before being overseas 6 months.

Other than that I'm mostly an electrical dummy, I have a voltmeter but barely know how to use it. I know the new battery is putting out 12.6 volts, that's about it. I haven't turned the key in fear I'll smoke something else. Typing through this I realize next step is to probe & see if power is getting to the 2 blown items above. I think I can get that far in the morning without screwing something up!

Any other tips & knowledge? Or someone that feels like guiding me on the phone? Either way appreciate it greatly!! I need to have it up & running strong again by Tuesday 😬

[octaneike]

Shorted the positive battery terminal to the alternator casing with a wrench when I was removing it. Yes I know what everyone is gonna say about that. 😆
I wasn't thinking. But I thought the battery was dead, it wouldn't take a charge with the trickle charger but I guess it had enough voltage to shock me and probably blow a fuse (#17) and the main relay (these according to the Electrical Troubleshooting Manual for the E24 and maybe others).

And I say probably, because the back story is that I keep it in storage connected to a trickle charger. I returned last week to find that part of the building without power, trickle chargers to both vehicles on that side were not live. Both chargers connected to a surge protector, to outlet that was dead. Actually I still need to test the surge protector to see if it did its job, or was just the outlet or line, breaker, etc. But most of that isn't visible to me, work for another day. Is it possible what I did was already done?

Anyhow after replacing the battery, had no interior lights, so didn't want to turn the key still knowing something is wrong. Disconnected batt, found fuse 17 (connected to just about all interior functions) was open, replaced that, tried again, still nothing. Disconnected battery, checked main relay and the 30A switch was broken. Replaced that, but with a generic one for the moment as I couldn't find the original Bosch part in stock. Still no interior lights. Pulled all fuses & relays, nothing else tripped or contacts in the distribution box appear burnt, zero damage anywhere. Removed the top portion of the dust box, no evidence of anything underneath. No smells of burning plastic nor hint of smoke.

Some forum posts describe a fusible link in the positive cable, but I don't see one. Is it embedded? The electrical diagrams don't indicate one either, but I could have overlooked it. What else?

My car is extremely original, down to all panels, glass, and even paint. The only modification is a Alpine Bluetooth radio to in place the broken original. But wiring appears to have never been monkey'd with, also no alarm or other non-factory accessories hooked to the positive. Car ran beautifully when I parked it before being overseas 6 months.

Other than that I'm mostly an electrical dummy, I have a voltmeter but barely know how to use it. I know the new battery is putting out 12.6 volts, that's about it. I haven't turned the key in fear I'll smoke something else. Typing through this I realize next step is to probe & see if power is getting to the 2 blown items above. I think I can get that far in the morning without screwing something up!

Any other tips & knowledge? Or someone that feels like guiding me on the phone? Either way appreciate it greatly!!

[shogun]

here on my website pics of the 2 fusible links on E32, same is on E34, that gives you an idea where to check, fusible links are always close to the battery. https://twrite.org/shogunnew/files/E...s_compiled.pdf On E34 it looks like this, pics https://www.bimmernut.com/forum/show...le-link-photos Maybe same on your model?

[bmwdirtracer]

Shogun, my very erudite friend, I do not find a fusible link in the E24's wiring diagrams, nor do I recall any on my E24 or my E28. I DO recall them on my E34s and E32.

http://wedophones.com/Manuals/BMW/19...g%20Manual.pdf

I'd tend to think the OP should be checking the main positive and negative connections for tightness and corrosion. I've sparked a wrench on many an alternator or starter over the years, never killed anything. Looking at the diagrams for this car, I'd have to wonder how such an occurrence could kill the main relay, too. Which would lead me to wonder whether the "generic" relay installed is actually a correct one. (The wrong relay can certainly fry the entire wiring harness, or just not work. I can't tell you how many times I've seen this).

Ike, if this were my car, I'd be chasing the no-crank condition not the interior light issue. Compare the relay you replaced with the new one: are the diagrams on the side EXACTLY the same?

[octaneike]

Thanks so far you two. There is definitely not a fusible link as mentioned, unless somehow embedded in the cable. Update from this morning - Fuses 16,17,18,19,20 are not hot. In the electrical manual, 16 and 17 depend on relay K5 Uploader (??), so maybe only in the acc position or run/start? 18-20 seem to be acc/run too. I do have battV at the main relay. All symptoms are the same b4/after relay replacement as stated above, the generic relay is not a cause but I also don't want it to be a contribututor to something worse, to your point! Here's a pic of the diagrams, to me electrically the same though not exact, correct? I still haven't turned the key so if it's not trustworthy I'll try to find another.

I'm going to find a new ground strap as this one is a bit frayed but certainly looks entact. After replacing
I imagine it's safe to check out the acc position and retest, but I'll wait for your feedback. Many thanks!20241118_125756.jpg

[bmwdirtracer]

No, the diagrams and the relays are NOT the same at all! The stock relay switches from open to powering BOTH 87 and 87a. The aftermarket relay switches between 87 and 87a, both of which need to be powered simultaneously for your car to start.

When you try to start the car now, (with aftermarket relay), you're turning on the fuel pumps, but turning off the DME. (EDIT: Or vice-versa)

[octaneike]

Thanks Chris! Well, I'm on the hunt for an original relay then. I still haven't turned the key.

So I did take the negative cable off to test it, has good continuity so I'm reinstalling it in the morning. The 3 positive cables all appear in great condition with solid connections. No corrosion at all. The one going to the main relay and the other going to the power distribution box aren't easily removable unfortunately. But the first is delivering battery voltage to the main relay connection, and the second I assume must be also, as starting with fuse 21 connection is reading the same. So assuming all cables & connections are good? Any advice on the other questions above, how to proceed other than finding an original-type relay? I really hope I don't have to take the fuse box apart ��

[octaneike]

So I just found the Bosch replacement. HOWEVER... First I checked with BMW directly, they didn't stock it but gave me the BMW P/N also, 12631710726. This P/N and the original Bosch# 0332014112, reference the one just purchased and pictured here. However the diagram is the same as what's pictured on the 3rd party part that you said was incorrect. Would you mind to please double confirm that this is indeed the correct replacement part quickly before I install it? Thanks so much!!20241119_140129.jpg

- - - Updated - - -

hi Chris hope this direct reply reaches you, can you please check the later posts in the thread, thanks much!!

[bmwdirtracer]

Okay, let's see if we can fix this. The "original relay" you're referring to is the metal one, correct? That has the correct diagram, as does the one in your last post. Note that the relay shows as open, and then switches to contact both circuits of 87. The black plastic relay in your earlier post does not do this; it switches between 87a and 87. The metal relay and the one in your last post match the wiring diagram I linked to. You may safely install the relay in your last post.

As for the fuses 16, etc... They are fed via terminal 30, via the UNLOADER relay, which is activated by the ignition switch being in the "start" or "run" position. They're not going to be hot until you turn the ignition switch on.

[octaneike]

Hi Chris, in the meantime of receiving your last reply, another guy locally helped me out and cleared up this exact thing you said, that I didn't understand. I never used the old relay, only the new replacement, and boom, everything worked! Thanks much for your help.

I still haven't troubleshot the non working interior lights, I replaced the fuse but still nada. But everything else on that fuse works,
so onto checking bulbs, then ?...