First of all, thanks Chuck, for the help last night.
On my 90 740 GL, the battery died for no appearant reason.
I jumped it but the battery wasn't charging, the lights got gradually dimmer all the way home. But the charge light on the dash never lit.
I trickle charged it over night and this morning read 12.5 volts.
I started it and got a reading of 14 volts with the motor running.
I turned it off and read 12.24 volts.
Next I pulled the small lead off the back of the alternator and with the key on but the engine off and got a reading of 11.5 volts.
Also, the charge light does come on when the key is first turned.
Is a voltage reg the most likely suspect?
I did check all the connections to be sure they were tight.
Thanks,
-Brent

if the battery has 12.5 volts and the small lead has 11.7, you have a voltage drop somewhere. check the grounds on the block for the alternator and the battery. check the engine harness for flaking insulation. something's not right. good luck, chuck.

Be sure the idiot bulb is OK. I think a bad bulb will interfere with charging.
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Don Foster (near Cape Cod, MA)

The bulb in the idiot dach light seems to be fine.
It comes on when the key is "ON", but goes off as soon as the engine starts

Sorry -- I misread your first post. My mistake.

Worn brushes can cause this. They'll touch the slip rings just enough to produce an output voltage that equals the battery voltage, but not enough to charge the battery. Because the output voltage is not lower than the battery voltage, the idiot light stays off -- misleading you into thinking the alternator's putting out.
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Don Foster (near Cape Cod, MA)