Caretaker boss Barry Ferguson, who took over the reins following the departure of Paul Ince in January, has seen the Seasiders extend their winless run to 16 matches following last weekend's 4-0 defeat at Watford.
They have dropped to 19th place in the Sky Bet Championship table as a result and are eight points clear of the relegation zone as they prepare to host Bournemouth on Saturday.
Black will assist Ferguson on match days as well as working in an advisory role two days a week.
The 50-year-old Scot has also held caretaker manager positions at Birmingham, Sunderland and Blackburn - he was assistant boss to Steve Kean at Ewood Park.
Ferguson told his club's official website: "I've got the man that I want in place. He brings loads of experience and unbelievable football knowledge.
"He has worked at Premier League level and the Championship, which is what I want. He is at a good age and is hungry to work with me, so I'm delighted."