Not charging, need help.

[visufish]

I have a 91 318i m42 and my charging system stopped working. I just put a new battery before the charging system broke. Below are what I've done so far:

Battery voltage when fully charged and engine on is 12.23v and goes down slowly.

- Battery light in the cluster doesn't turn on. I have a spare cluster and swapped a working bulb for the battery light and it still doesn't turn on.
- I tried to swap with my spare cluster and battery light still won't turn on and system doesn't charge.
- replaced the alternator with new voltage regulator and ground wire but still won't charge, voltage stayed the same and slowly goes down.
- got a new rebuilt alternator and tested ok in shop but still no charge.
- checked continuity between battery and alternator main wire (green wire) and it was reading ok (2.0+ ohms)
- I looked at my ground straps at the passenger side engine and they look ok to me.

This charging issue happened after I did the power steering delete. Although I double checked everything after I raised the engine and I didn't see anything moved or disconnected.

Any help would be appreciated. Thanks!

[jlevie]

The first task is to figure out why the warning bulb isn't working. That bulb provides exciter power to the alternator and without exciter power the alternator won't charge. If the bulb is good, there is a problem in the cluster or in the wiring.

BTW: A fully charged battery will be at 12.7v. A battery at 12.2v is at 50% of full charge.

[Gregs///M]

Looking at the engine ground is not enough. Remove it from the car, wire brush all contacts (on cable and in mounting points,) then reassemble. Recheck your voltage at idle.

You can also measure voltage directly from the alternator while referencing the body of the alternator (black wire on meter.) Should be near 13.5 volts at least. Should be the same at the battery +/- 0.1 volt.