Yes that is the collector for the black wire. The yellow with the black tracer goes to the buzzer that tells you the lights are left on when you open the door.
The voltage limiter. I goes in the 12 volt keyed female slot on the circuit board and the limiter plugs in the same slot with it. I am not sure on the buzzer but I do believe it most likely came with certain option packages. It is possible your car did not have that option. The main harness is made for all models so if it was an added option it would plug right in.
I was not sure on the black white tracer wire. Glad you caught that. But look at the schematic above it shows the red going to the flasher then changes to pink to the switch. I would agree with you that both red and white go to the brake switch. But why do they show the flasher in the middle of the circuit?
Don't let it confuse you. At the flasher there are 2 pinks piggy backed at the one terminal. One pink is from the fuse block so it is constant 12 volts and the other pink just goes over to the brake pedal switch. The flashers other red wire then feeds the 4 way flasher switch. Red is not the source of the 12 volts. Pink is.
