The 24-year-old spent last season at Stanley before joining Crewe during the summer on a two-year contract.
Molyneux, who has made nine appearances for the Railwaymen, spent two months on loan at Rochdale earlier this season.
"It feels like coming home," Molyneux told BBC Sport.
"They were special times for me last year. I hope that we can recreate them this season. I believe there's more quality in the squad now as a whole than last season."
Molyneux scored eight goals in 42 appearances for Stanley last term.