I have a 2002 ford explorer xlt , it won't start. I replaced the starter that wasn't the problem. Then I had a locksmith come to try to reprogram my key ad even cut me a new one but the equipment fail

Does the engine crank when you turn the key? If so then the problem is not with the key. If absolutely nothing happens when the key is turned to the start position, there may be a malfunction with the security system blocking the starting procedure.

I had the same problem and everyone told me that it would cost me thousands of dollars but it only cost me five dollars

When you try starting it do you see - - - - on the odometer