What is the ruling on dealing with a customer who buys refrigeration spare parts to supply them to a winery, and what is the ruling on the money earned from this transaction before I became aware of it?

If the seller knows that the buyer will pay for or sell these parts to a winery, then it is not permissible for him to sell them, as this constitutes aiding in sin. Allah Almighty has forbidden this, saying: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression." However, if the seller does not know this, then there is no objection. And what was sold before knowing the buyer's situation is not subject to accountability.