In my 76 280c 114073 chassis. P.ower antenna wires are disconnected near the f 20 fusebox smaller pre fuse behind main fuse box . theres another red /blk wire coming fr main fuse box connected to the f20 . in wiring diagram it says f20 box is for aux fan . then on batt buss chart in diagram says red blk wire goes from f1 to f20 . question is is this a trigger wire ?? trying to relace f20 fusebox whats correct way to connect these wires ? since diagram doesn't cover trigger wire in manual

hap:

The power supply for the auxiliary fan originates on the hot (battery) side of fuse #1 (in the main fuse box). Red/black from fuse #1 to aux. fuse. Red/black from aux. fuse to aux. fan relay (pin 30). Yellow from aux. fan relay (pin 87) to aux. fan motor.

Thank you ! FRANK