e46 intermittent electrical problems
I bought a used 2003 330 Convertible a year ago. 3 months ago, I had the alternator light come on. It would come on first time I drove the car, especially with AC on, but would only stay on til the temp gauge hit 3/8. It did not come on every morning...took it to my local bmw guy (non-dealer), and he said it was alternator. Replaced with a rebuilt Bosch, and thought all would be fine. A few days later, the same symptoms occurred. It continued to be random, not even happening each morning. We replaced teh battery.
After the battery was replaced, it was a little better, came on less frequently, and I thought it didn't happen when the AC was off - but recently it occurred when the AC was off as well. One morning last week, instead of the alternator light coming on, the indicator which said my left front headlight was out came on - this time, it was after the car had been running for 3 miles, and late in the day (altho the car was parked all day). I flipped the lights off and on, and it went out.
Since then, I've had the head lamp indicator come on a couple times, and the alternator light come on. This morning. Both came on at the same time. They did not go off when the car temp hit 1/2. I turned the car off (after about 2 miles), and when I restarted it 3 min later, the headlamp indicator was not lit, but the alternator still was. While the car was running for the next 5 min, the alternator light went out, andthe headlamp indicator came back on. The AC was not running except when I started the car the first time - and immediately turned it off.
Any ideas what might be going on here. Is there any good way to diagnose this without replacing all the things that might be symptoms, rather than true cause. All other electrical items seem to be ok. Also, when the headlamp indicator light is on, the headlamp itself if off.