Editing Openai/6940b2df-db80-8003-b707-4cc5cbedf6d9 (section)

=== Assistant: All good — and that detail changes the whole picture. ===
All good — and that detail changes the whole picture.

11.4 V with ignition ON (engine not running) is low. Not “a little low”… low enough that BMW modules can get weird, the CAS/DME can throw a fit, and cranking performance (and especially spark/fuel control) can become inconsistent.

===== If you’re measuring at the battery posts (not the cable ends): =====
* 12.6–12.8 V = healthy, fully charged (typical)
* 12.2 V = about half charged
* 11.8 V and below = basically drained/weak
* 11.4 V = either deeply discharged OR the battery is bad OR you’re losing voltage through a bad connection

So before we blame the alternator (can’t test it until the car runs) or even the power distribution box, we’ve got to prove where the voltage is being lost.

==== Get a multimeter and take these readings with the car sitting (ignition OFF first), then ignition ON. ====

===== - Ignition OFF voltage = ______ =====
* Ignition ON voltage = ______

===== - Ignition OFF voltage = ______ =====
* Ignition ON voltage = ______

Interpretation:
* If battery posts show 12.4+ but jump post shows way less → distribution box / main cable / connection issue
* If both show 11.4-ish → battery is discharged/weak or there’s a heavy draw happening immediately with ignition ON

==== 1. Hook the charger to the underhood jump post + ground (or directly to the battery posts in the trunk if you prefer). ====
# Charge the battery fully.
# After charge completes, let it rest 30–60 minutes (surface charge fades).
# Re-check voltage at battery posts.

If it won’t come up into the 12’s, the battery is either failing or there’s a parasitic draw dragging it down fast.

: 

==== ### ====
* Select battery type (AGM vs flooded)
* Enter the CCA rating from the battery label
* Run test If it says “Recharge & Retest” — do exactly that. Testing a discharged battery gives misleading results.

===== - Run the cranking test and watch minimum voltage while cranking - If it drops below ~9.6 V: battery weak / starter draw too high / bad cables - If it stays strong but won’t start: now we chase fuel/spark/start enable =====

===== Ignore alternator testing until the engine actually runs. =====

==== This is where your melted power distribution box and connection points become prime suspects. ====

===== - Battery terminals tight and clean (no rotation by hand) =====
* IBS on the negative cable not cracked/loose
* Rear distribution panel (melted/warped) = replace it — heat damage = internal resistance
* Underhood jump post: nut tight, not corroded
* Chassis ground points: clean, tight
* Engine ground strap: intact (common silent killer)

===== If you want one test that cuts through the noise: =====

Positive side drop
* Red lead on battery positive post
* Black lead on jump post
* Ignition ON / crank
* You want a small number. Big number = resistance in distribution box/cable.

Ground side drop
* Red lead on battery negative post
* Black lead on engine block
* Ignition ON / crank
* Big number = bad ground path/strap/connection.

==== Low voltage can cause false symptoms. So do this after you get solid voltage. ====

===== - Run a full vehicle test. =====
* The key question: Does the DME (engine computer) communicate? - If NO → power feed/fusing/distribution box/wiring is very likely. - If YES → go to live data while cranking: - Engine RPM present? - Start enable? - Injection and spark plausibility faults?

===== - Check CAS for start authorization =====
* Check DME for RPM while cranking and fault codes

==== Right now, 11.4 V key-on is a warning flare: either the battery is not truly healthy/charged, or you’ve got voltage loss through that melted distribution panel / cables / grounds. ====

If you tell me just two numbers, I’ll point you to the exact culprit:
# Voltage at battery posts with ignition ON
# Voltage at jump post with ignition ON

And tell me one more thing: when you try to start, does it crank, or is it click/no crank?