They're used on the dashboard harnesses of 1984-1988 Audi 5000 Turbos, and 1990-1994 V8s. (Odd they aren't listed on the NA cars... explains why I didn't see any on mine, it was an NA)

Guessing by the lengths of wire on the diagram I would say they live under the main fuse box, above the dead pedal, inside the dashboard.

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.