alternator light on with key/ign. off

[lowride]

Hello;
Problem with a 1964 230SL
The alternator light is on at all times with the ignition off. When key is turned to run and also to start, the light goes off and remains off when engine is running. I had checked the charging system and it wasn't charging. I removed alternator and found bad diodes. I was unable to find parts locally so I replaced the alternator with a remanufactured 35 amp alternator. After reinstalling the alternator, the results are the same but it now charges right where it should be 14.5 volts. I also replaced the regulator with a electronic unit but tried it with the original one as well. Results were the same, light on with ign off, on when ign. switched on or started. Any help would be appreciated. Additional note; all the engine wiring is pretty crusty and painted over, but appears to be otherwise ok.
Any help is appreciated.

[Jonny B]

Does the car start alright?? That is, full crank speed? Has the wiring been messed with before you had the car? On the later cars (280 SL) the alternator light serves a double duty as a door ajar indicator. Could someone have put in this circuit from a re-wire?

Are you disconnecting the battery when the car is stopped to prevent the drain?

[Garry]

It also can serve as the indicator light for low fluid in the brake reservoir (float with a pin hole) when the door is open and goes off when the door is closed or the key turner to on.

Garry

[lowride]

Does the car start alright?? That is, full crank speed? Has the wiring been messed with before you had the car? On the later cars (280 SL) the alternator light serves a double duty as a door ajar indicator. Could someone have put in this circuit from a re-wire?

Are you disconnecting the battery when the car is stopped to prevent the drain?

The car starts perfectly, yes, some of the wiring is questionable (no plug for alternator had to fab connector, yes they are correctly hooked) Thought about door sw. not an issue. Yes I am disconnecting battery.
Thanks!!!

[hands_aus]

Hey lowrider,

You installed a re-maunufactured alternator.
Did it have new diodes installed or were just the brushes and bearings replaced?

[lowride]

The alternator was a complete reman, so I have to assume the diodes were replaced as well. However I think my next move is to remove the alternator and check the diodes to see for myself.