Bill,
You got lots of good responses, but a couple don't apply to your car, in terms of which lights are tested.

• The License Plate bulbs haven't been part of the BF sensing since about 1977. So they aren't among the usual suspects for most of us.

• My '93 greenbook diagrams (and all earlier ones I've seen) show no testing of Parking Lights (front or rear). Must have added them after '93 if they are on Tom's diagram.

From '79 thru '93, the BF sensor checks 3 lighting groups:

1. Both Brake Lights + High Light (Operation and lights can be tested with key OFF or out)
2. Both Tail Lights (Need Key ON + Light Switch on 1st position to test BF operation)
3.Both Low Beams ( Key ON, Switch on 2nd position to test BF operation)

By trying these one at a time, it's easy to identify which of the 3 is bothering the BF sensor.
--
Bruce Young,
'93 940-NA (current)
'80 GLE V8 (Sold 5/03)
'83 Turbo 245
'76 244 (lasted 255,000 miles)
73 142 (98K)
'71 144 (track modified--crusher bound)
New 144 from '67 to '78
Used '62 122 from '63 to '67