I don't know about the Caddy, but my Silverado had this problem.
I still have the scar on my hand from laying in the snow/salt/shit last winter and using my Sawzall to cut that damn secondary latch off.


Here's mine after I cut it off (actually shown upside down.) Any idea's why it wouldn't come down????
So I had to replace it because I (obviously) cut the cable off. $130 later . . .
It just slipped into a slot and just one bolt. Just an FYI, if you've kicked the hoist, that bolt holes might be a little tweaked
Here's a picture of the new one and old one side-by-side on my workbench
I tried WD-40, kicking, swearing, prying, everything and it wouldn't drop. Maybe since you can see yours you can get some oil or something on it. Good luck!