Fuse on the far left , 20 amp , is fed from the fusible link at the starter solenoid , it's for acc. power . The fuse next to it , 20 amp , second from left is for chassis power , this is the one you need to trace out .
Yellow wire from it should be 12 volts to the key switch , when you turn the key to on position you should have 12 volts going out on the red/black wire .