Bought the car and was told main relay was bad. Replaced relay, car was good for a week and then wouldn't start. After replacing ECU everything has been great, except now the power windows, locks and AC are not working. Checked fuses and that's about it. All worked fine before ECU was replaced.

It seems like maybe an easy fix but I cannot find anything online related to this issue.

Please help. Thank you

 

If you kept the old ECU, put it back in and see if those work. If they do, then the replacement ECU is bad.