1968 The purple wire

My old reliable Mustang wiring book does not show the circuit, so I bought the Jim Osborn Electrical Assembly Manual. The small print almost pulled my eyes from their sockets, but sure enough, there it is.
Thanks for all the help guys. Now I'll get things squared away.

Neil

It is a hard one to read!!! Anyone know what that switch is? I took a quick look and did not see where the violet/white line the violet jumps to thru the red connector goes... but it was a grimy old harness and did not do any continuity...

???

Its the brake differential switch on the distribution block. Strange nomenclature.

Neil