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The warning lights go out after engine start-up because they have lost their ground side.
That connection is made through the alternator rotor windings. It goes from the instrument cluster to the infamous gray connector on the firewall and thence through a wiring harness which goes under the front of the engine, ending as the thid red wire connected to the back side of the alternator.
When the alternator begins to charge, that negative polarity is lost.
If that thin red wire is grounded somewhere along that route, the warning lights do not lose ground, so they stay lighted.
The thin red wire also brings 12 volts to the alternator rotor and makes it magnetized just enough to start the current charging process. So - no 12 volts means no charging, too.
Quick test is to use a voltmeter across the battery termials. Engine stopped, should be 12 volts or above. Engine running should be 13.5 to 14.5 volts, if charging is taking place.
That thin red wire can be grounded in several places. First, it is a part of the harness (240s 1980+ to 1988) that is subject to insulation crumbling. Have a look at the wires coming out of that gray connector, the red one to the alternator and the black to the oil pressure sensor.
Second and in addition, the harness running under the engine front has normal aging problems. As the harness covering looses flexibility, the metal tabs holding it in place can abrade themselves into the wires and can short one (or more) of them to ground.
Battery usage is not very high unless lights or other heavy draw items are used a lot. If your commute is done without headlights, wipers, rear window demist, etc., the battery can last quite a while without charging.
There is a fix. Do the checks and post back.
Good Luck,
Bob
:>)
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