Everyone is on the money.
That motor is a 75-77 type. It needs to be put out of its' misery! Although the cap is broken , it will still work like that.
You can purchase the same style motor on eBay for about $185 and probably less.
Just make sure you position the switch plate for an e body.
The switch you have is a 2 speed and the source of your problems. Get a 3 speed switch. It is smaller and has
a rectangular metal box attached to it. 72-74 e bodies had 3 speed switches whereas 70-71s had variable speed switches.
The linkage looks fine.
Jules
