Saturday's 2-1 defeat to Shrewsbury extended North End's unwanted club-record run without a home league win to 11 matches.
"His job is to fix it (and) I expect him to fix it," Ridsdale, who is employed as an advisor by Lilywhites owner Trevor Hemmings, told BBC Radio Lancashire.
"If you're not winning football matches, everybody's under pressure. Is there pressure to start winning? Of course there is.
"Football is all about winning and we're not at the moment.
"Is everybody at the club under pressure? Yes they are. Does that include the manager? Of course it does.
"He knows, like we all know, that our supporters want to see us win. The pressure's there, but to some extent it's coming from ourselves.
"The last thing I want to do is spend my Saturday afternoons watching losing football. It's not what I'm used to and it's not what I want to do. My knowledge is that the manager feels exactly the same way."