The VW beetles used two types of coils, one with built in resistance, and one without. Generally, the Bosch blue coils had resistance and the Bosch red coils did not, but you were never sure unless you measured them because the coils were made in several different countries and just named "Bosch". The black VW coils could only be determined if they had resistance by measuring.

Glad it worked out for you!

AV8TOR