1994 GMC Safari

Electrical problem
1994 GMC Safari 6 cyl Two Wheel Drive Automatic 189700 miles

I'm replacing the fusible link connector at the firewall. I got a little ahead of myself by removing the connector. Now I have to figure out where each of the fusible links go. There are (2) 2.0 SQ MM and (2) 1.0 SQ MM going to 4 red wires. One is easy. It goes to the blower motor. Another I can trace to a unit(?) Mounted on the firewall below the brake master cylinder but I don't know what it is. Maybe the ECU? Two go inside to the fuse block. My question is which goes where? And is that unit under the master cylinder the ECU?
June 23, 2009.

link A--black--antilock module

link B--black-- stop/haz fuse--power acc C/B--ignition switch

link C--rust-- headlamp switch and other lamps

link D--gray-- hvac blower relay

Jun 23, 2009.