My focus will not start. I have replaced the starter and tested it to make sure it works. I have cleaned the body ground connection. I have replaced the negative cable with pigtail from the battery. I have tested all of the fuses and wiring that are connected to the battery box. There is power with the engine to body ground test. When I turn the key all of the electronics work it just will not start. The starter is getting power. Everything I have read indicates it could either be a ignition switch issue or the TCM. How can I find out which one it is?

 

If I understand everything you are telling us,
when you turn the key to start the starter is working, but the the engine will notbegin to run, is this correct?

If that is true, what is the check engine light doing while the starter is operating ?

Do you hear the fuel pump run for the usual 2 seconds when you first turn the key on?
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One question relates to electrical and the other relates to fuel , maybe we can help pin down what is or is not happening..