Main Relay Power Circuit
WARNING: This page is about a different car, the 1988 Buick Riviera and 1988 Buick Reatta. However, it is still accessible from the selected car via links, so may be relevant.
When the relay is energized by EBCM main relay enable output (12 volts on pin No. 8) switched battery power is provided to EBCM pins No. 3 and 20 through circuit No. 850. Main relay power comes from a main relay fuse on circuit No. 640, through a fusible link on circuit No. 2 at battery junction block.