I have a 1995 940 that has its first “real” problem and sadly has left me stranded for the first time. 14 years isn’t too bad of a track record.

If I put a properly charged battery (12.65 V) into the car, the battery will discharge. Today, for example, the battery charged at 12.65V sat in the car for 12 hours and is now registering around 12.25 V. All accessories and idiot lights work before attempting to start the car, but after starting it, only a click happens. Then all power is lost: no dome light, no radio, etc. Nothing. Battery still registers at the same voltage before attempting to start it.

I have also charged up the battery and then immediately tested the alternator at the battery terminals without driving the car. Under no load and at idle, the alternator produces 14.1 V. At 2k RPM and under load—fan on 5, hazard lights, both seat warmers on, day time headlights on, radio, and windshield wipers—the alternator produces 13.7 V.

I’d like to perform a current draw test on the car, but I am not too sure how to perform this test. Would someone kindly explain how to perform it.
Is there anything else I should be looking at. I need to get this car ready for work tomorrow.

Jeff