if you detail this diagram will find the only diff between lights on buzzer and not is the diode to link the parking light signal to the buzzer. I edited te diagram because I was showing diff stuff at FBBO.

The reason for the diode is just to not turn on the parking lights when you insert the key. This is because both signals drives positive. On 71 was changed, using negative for key sensor instead

And adding a plus, on 70 this system was deactivated when you put the key in RUN, so only buzzs when car is off. Since 71 the buzzers remain buzzing ( if needed ) no matter the ign switch status.