Happy new year all!

I just picked up a used '93 240. Nice car, but not without a few problems . . . .

One of those is the charging system. Symptoms: Battery goes flat/not charging, and not all the warning lights come on with key "on" and engine not running. When engine is running, some of the lights--including battery/charging light--flicker faintly.

I've done a number of checks:

With key on/engine off, I checked for continuity between alternator terminal 61 on the alternator and ground; reading is ~20 ohms. (should be ~ 0 between 61 and ground, correct?)

With key on/engine off, I grounded the wire from the charge/battery warning lamp to alt#61--all warning lamps, including the battery/charging system warning light--came on bright and steady.

Checked for good ground between blue wire at back of alternator to battery negative terminal, good continuity, no resistance (>0.1 ohm).

Pole-to-pole battery voltage with engine off = 12.4 volts

Pole-to-pole battery voltage with engine running = 11.8 volts

So . . . is the alternator dead (diode/s?), or is this a problem that could be solved with new brush pack/regulator?

Any insights/BTDTs/additional checks/considerations would be GREATLY appreciated!

Thanks in advance!

Steve A-