87 and 87a are the Normally Open and Normally Closed contacts for the relay:

<img src="http://www.rowand.net/Shop/images/HeadlightRelayWiringDiagram.jpg" alt=" - " />

Some relays are "make before break" and some are "break before make", if the former, you can have a connection from 87 to 87a for a brief moment while switching. Not sure what the typical Bosch relay is set up like.

<small>[ April 14, 2003, 03:11 PM: Message edited by: 4Crawler ]</small>

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