Bill,
There are TWO versions of this switch. The only difference is the harness on one is longer. The switch mechanism itself is the same. I found a NOS one at one point b/c like yours, my switch went bad and had the same symptoms. I installed it on the column, but when I went to plug it in to the main harness, it was too SHORT and couldn't connect!!!
You wanna talk about an unhappy camper...
Turns out that based on the build date of your car, they had one that had a shorter or longer wiring harness w/ the gray box connector. I wish I'd saved the info on what the build date cutoff was when they switched over to the shorter 70 version - I'm sure its annotated in older parts catalogs. Hopefully someone will follow up and respond on this post with the date.
My car was an early build date car, so it required the LONGER version which thankfully I sourced.
Also - this may sound dumb, but there is a small plastic shipping plug that goes in sideways on new ignition switches that keeps the plunger switch from moving in or out. Sometimes the shipping plug is white or black. regardless, if you don't take it out, the switch won't move or work.
I recall feeling like an idiot the first time I replaced an ignition switch and wasted some time trying to figure out whythe switch was "frozen" before I realized the small plastic shipping plug was supposed to be removed.
regs,
Steve