I am in the process of cleaning up the engine wiring harness and labeling everything in lieu of the rebuilt 455. And I'm having trouble trying to find where this particular wire goes. It's a black and yellow wire that connects to the "windshield washer solenoid" and goes to the "downshift sw and solenoid." What is this for and where is it? I'm referencing the wiring diagram from the website below:

http://userweb.suscom.net/~jasonrogers/69firebirdwiring.htm

The diagram I'm looking at is of the 1969 Firebird Front and looking at one of the bulkhead connectors. Anybody have any ideas? Thanks.