Wiring gremlins

There are a whole bunch of differences in the 69 harness and the 70 up harness including that console harness.
if you have all 69 car ( Ignition in the dash, etc. ) it will be easier to restore the correct wiring harness than to adapt the later model harness to the pre 70 car.
To do it right would include a few upgrades to the 69 harness in problem prone areas. Accesories like hazard lights, wipers, horn, should and would remain unchanged.
Those are where your problems will be multiplied in what you are trying.