Java,
I have a 72 and the LB is connected to L. The LB/BK is connected to R.
The diagram you are working from is wrong. Correction- maybe not wrong but for an earlier car.
There is a Pantera TSB#13, article 106 that discusses the 'Hazard Warning Switch Connections' and references a figure on the article for the correct wiring-to-hazard warning switch connection. I wrote down the wiring from my switch before removing it for repair. It matched up to what is on the TSB.
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