The LED lights on the buttons do not flash a code. Still it could be logic related since the fan speed is probably controlled logically (even in manual) and stepping on the brake possibly creates a power spike or logic state of its own. (?)

Then again stepping on the brake also creates a kinetic condition on the fan itself or wiring.

But right now I don't have a clue where to start looking for the fault. I could take it to a dealer or indy, but not if they aren't going to know where to look. Plus it would work perfectly that day ;)

Is this climate control module located in the dash? How about the fan power stage module? I have a vague idea that the fan itself is near the passenger knees, and probably complicated to get to. But I should rule out mechanical problems first. Maybe debris is leaning away from the fan when I stop. I have changed the pollen filter but still something could be in there. Or wire contacts could be corroded?

Thanks!
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98 V70 GLT black 54k