I'm familiar with how the bulb failure light throws an indication when it senses an imbalance between left and right bulb current draws.

The rear fog light on the 93 940, as some of you may know, doesn't have lights on both sides; there's only a bulb on the driver's side. So it may not be that surprising, when engaging the single-sided rear fog light causes the bulb failure light to illuminate (the single rear fog light works fine). But it surprises me that this single-sided bulb would even be wired through the bulb failure relay, and I would have thought that if this is the case, the owner's manual would at least make note of this in either the bulb failure or fog light section.

Is this bulb failure indication with the rear fog light normal, or is there some other problem? I'm not aware of any other issues with the rear lights, so I wouldn't expect that there's an interaction from other bulbs playing into this.
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David Armstrong - '86 240(350k km?), '93 940T(270k km), '89 240(parts source for others) near Toronto