This all started with noisy bearings in the alternator in my '70 280 SL.
I had the alternator rebuilt by a local shop and reinstalled it with a new Beru regulator.
Before the rebuild it was probably charging since the red charging light was off with the key out or inserted and only on in the process of starting.
Now the red charging light acts as follows:
Key out Light ON
Key in Light ON
Position 1 Light ON
Position 2 Light OFF
Starting Light OFF
Running Light OFF
The rebuilder insists there is a short in the light circuit. Any ideas where it might be?
FYI: The voltage across the battery terminals is 12.6 at idle and increases to 13.7 volts at 2500 RPM. The voltage between Alternator B+ and ground reads about the same. The rebuilder showed me it was able to make 14.6 volts on his bench test.
Thanks,
Paul
PS I just found the alternator page in the tech manual and will follow the tests indicated there.
Hello, if it is your charging light that's on, you must be getting a permanent +ve supply at the lamp somehow, with the ignition key out, which is wrong. You should only see +ve there with the key turned. I wonder if you have a problem with the ignition switch, and fuse 2 is getting a +ve feed all of the time. Fuse 2 also feeds the horn, wipers and cigar lighter, are these working without the key in? Having said that other fuses would also then have a permanent feed without the key in, including the fuel pump, and i would have thought you'd notice that, but worth checking in the first instance