The fuel pump runs with out a key in the ignition. I just recently replaced the fuel pump, ignition switch and cylinder. It didn't start doing this till I replaced the cylinder. So I thought the switch was bad and replaced it but it still runs. Could it possibly be a bad cylinder?
My car has an automatic transmission.
In most cases, this problem is caused by a short in the ignition cylinder. It’s possible that perhaps you have a grounding issue or that one of the multiple wires from the main relay are continuing to supply power to the fuel pump. You might want to have a professional mobile mechanic complete an electrical problems inspection if you can’t find the source of this issue.