66olds_toronado

I have a 1966 Toronado with a headlight that won't go up any more. I looked at the vaccuum canister and the parts surronding it but I am not 100% how to troubleshoot it. It looks like a bolt is missing frrom on of the arms that attaches itself to the body but even after reattaching it the light would't rise. I'm also not sure how i can tell if the canister is bad. Any help would be appreciated.