They might try to contact your employer once you default. However, wage garnishment is a legal process and they need to win a judgment to garnish your wage. But they might send a notice of voluntary wage assignment to your payroll department. Most of the payday lenders get a voluntary wage assignment contract signed by debtors.
Your employer can dishonor your request and you can cancel this agreement any time. Yes there are few consolidation companies that work with payday loans. Please check your PM, I have sent you the information.