Yendor1972

Sounds like your alternator voltage regulator is toast.

1) A bad voltage regulator will cause all sorts of things to happen. The system only operates critical items to get you to the side of the road. Nothing else. That includes shutting down the water pump and fans. (this happened to me)
2) A proper visual inspection is needed. Each module needs to be inspected, even the radio amp and XM modules. My XM module had some corrosion on it, that cause a short that would drain the battery over night, a new battery. I could jump the car, get it started and because the power demands were high enough I saw all of the lights you are seeing now. Once I was able to bypass the XM module I tried again. I was then able to confidently test the power production of the alternator and it was bouncing around all over. I installed a new voltage regulator (they are replaceable on the BMW alternator, no need for a new alternator) and the issues were fixed. I went from a gremlin infested pile of confusion to a car that runs like a champ.

PM me if you need additional help, I'm willing to talk you through things. I am a former avionics tech and RF engineering tech, I now supervise a Caterpillar dealership power generation (industrial generators) group .

pavjayt

Thanks Yendor1972 for your detailed reply. I checked the voltage at the battery when the I turn on the engine and it is steady at 14.4V to 15V depending on what I turn on in the car obviously before it shuts all the electronics off itself. Here is my plan for the weekend. Using a multimeter connected in current measuring mode to the battery, will see how the current draw varies while going through all the fuses (unplugging and plugging). Hopefully this can help a bit in this issue tracking. Will get back with results.

donpb

- The regulated voltage (engine running, battery charged, accessories and light OFF) is usually between 13.2 and 14.5 depending on temperature and operating conditions. If the voltage is higher than 14.8, the voltage regulator is most likely faulty.

pavjayt

Ok guys, I know its been a while I updated on my E61 situation. Finally bought a clamp meter that goes with my fluke, amazing thing btw, makes life much easier when you are tracking now drain issues on anything.

Anyways, here are my observations, with everything shutdown there is constant 5A drain and if I leave the battery connected, it drains the battery to ~2V by next morning. Anyways after tracking down, it comes down to this cable in the engine bay. If I disconnect it, drain is ZERO, once I connect it back, it goes to 5A.




Now I am open for suggestions.

seanjordan20

Follow I under the car to make sure it's good? Look in the truant and make sure the connection is bad. You should be able to find in by following the positive cable from the battery going under the trim carpet. There's a bolt down point there

seanjordan20

Video to where it is.

seanjordan20

Also check to see if the module under the spare is good (if it hasn't been relocated yet)

donpb

If that cable goes back to the battery and the drain goes away when disconnected, then its not the cable at fault or else you'd still have a drain issue.

pavjayt

Thanks Sean for all your leads.

I am a bit confused. At the battery, there are two hot wires, one goes directly to the fuse box in the trunk above the battery and the other one goes to the front. While trying to isolate the drain, I left only the hot wire going to the trunk fuse box overnight while there is no current draw reading I can see on my meter, the battery voltage hasn't changed much by morning. Next day, left the other hot wire going to the front connected to the battery, constant drain of 5A and battery went flat by the morning.

At this point, charged the battery full, kept the hot wire going to the front connected and started with the fuses in glove box, the drain hasn't changed with the same result for the fuses in the engine bay.

Now my question, how do both of these fuses boxes get power? Is it from the same hot wire going to the front from the battery or is this cable solely the one that is being connected to the jump start clamp in the engine bay?

After looking at the wiring diagrams, the second hot wire at the battery is solely going to that jump starting terminal in the engine bay (with probably one connection point in between X2219), but from the symptoms that I am seeing, that is not at fault. Then the cable that I am connecting/disconnecting at that clamp is the only one that goes to starter and alternator. So, it should be somewhere in between, time to trace that cable.

Also, could you please elaborate on what modules you are talking about in the spare wheel well area? Will go through your link now

pavjayt

When the cable is touching that clamp (jump starting positive clamp) as shown in the picture, there is constant 5A drain, but when I disconnect it, there is no drain. Looking at wiring diagrams now to see if I can make it out.