Hello, I have the following problem. When I start the engine, the battery and the off-switch will light up. When I reach 2000 revolutions, they will go off. My on-board voltage will also go up to 13.7 volts. What I have already found out about the search is probably my coals are down. My question now is what kind of alternator was installed a Bosch or a Weila (probably wrong written) ? It revolves around an Audi 90 Built. 8 9 2.3 Quattro 10 V. A buddy of mine said if it is a Bosch there are no problems to exchange the coals and regulators. Only if it is not a Bosch the coals cannot be exchanged. Thanks to you.