Firstfives.org

Theotherotter wrote: Mon Mar 30, 2026 9:20 pm Outstaning content - thanks for documenting this.

No problem. The obscure interchange possibilities are often invaluable for future attempts.
Robert

Here are a few more interior side completion pics. I'm calling this the AC half system. I brought the aluminum hard lines (Vintage Air) through the firewall and placed the Vintage Air drier as well. Routing follows very closely the stock E12 system using my 530i for reference. The half system is ...

The AC project is now half complete with everything done on the interior side. It's worth highlighting some of the work on the evaporator box where a bit of creativity was required. Having acquired 3 different boxes, I was able to choose the most appropriate and best condition unit to rebuild. I ...

Hey Eric. Not yet, but getting there.... My strategy is doing all the interior work as the first phase of the project. I'm currently bending the aluminum hard lines going through the firewall. The second phase of the AC will be doing all the work in the engine bay beyond the receiver/drier. I'm ...

Heater core enclosure now rebuilt and installed. I had acquired a used box from a 79 528i to rebuild on the bench and swap in. This component was fairly straight-forward. I took everything apart, cleaned it, and lubricated moving parts. The heater fan motor was new as of 2018 and reused. New parts ...

Yeah, there are plenty of workarounds, but you do need that voltage drop there in a closed circuit to start the alternator. A workaround could be wiring another bulb or resistor in place of the instrument cluster bulb. I think it's the only thing in the cluster that's more than just driver ...

I've finally shifted my focus back to the AC installation on the Euro restoration car. Talking with Ken (0257) back and forth on the refresh of his AC system over the last year helped me plan and solidify what needs to be done. The interior really boils down to acquiring/rebuilding these three ...

Follow up on the alternator replacement:

I sourced a third rebuilt unit of this 80A alternator direct from Germany. Unlike the Bosch units, the voltage difference between the B+ and D+ terminals is about 0.1V at various operating conditions, which is definitely better. It seems to be charging the ...

Bravo, Robert, your meticulousness is always appreciated. Do you know if this would be the same with the AL41X on the 1979-81? Is that merely a 65-amp variant of the AL46X?


I suspect these Bosch alternators are fairly similar and you could follow the same procedure with the appropriate ...

I think the problem is solved. I acquired a second rebuilt AL46X alternator from FCP Euro and it was electrically the same, so I decided to fix one of them. My interpretation of all this is that Bosch is not rebuilding the alternators to original specs. The rebuilt alternator charges and passes an ...

Unfortunately, the older E12s before the facelift are even rarer here. I've only got side doors on my 77s.

It's a long shot, but try looking through the vehicle index here for the early models. Ulrich went around the world cataloging every E12 variant he could find. He did a photoshoot on mine and ...

I'm guessing, but I think you've got bad diodes, given the bidirectional conductance on D+ and the voltage discrepancy. Replacing the rectifier plate should resolve the faint battery light and stabilize the D+/B+ voltages unless there are other problems with the alternator. I might exchange the ...

Anybody done this before? I've been chasing a weakness in the charging system on the 530i for months. The symptom is a very faint flow of the battery light. It's so faint it actually goes unnoticed unless it's night. This old post is similar, but never presents the actual solution.

www.firstfives ...

Putting the needle back on? I've never pulled it off do fix odo gears. I have removed the screws that hold the face on to loosen it up and get more working room, but never pulled the needle off.


Yeah, this was about 5 years back in the heard of COVID. My repair either required removing the ...

Most obvious route for the E12 is to get the transistorized ignition of the later 80-81 528i. I did this a long time back (see FAQs), but it's intimately tied to the FI system as I recall or at least the way I did it. Maybe possible on a strategic subset of those parts. I'll leave that to somebody ...