My wife's CX9 had some starting issues recently. Turned the key, click, no starter engagement. Replaced the starter relay, ignition fuse still good, charged and tested battery, alternator and starter. Said it all were good. Car starts fine now, but there have been a few times the car would not start. Could there be an issue I am not seeing? Is the starter going out? Possible wiring issue (did not see a fuse on the cable)?

 

Assuming (and that's a BIG word) all those parts you replaced were actually tested as failed or failing, I suggest to look at the ground cable from the battery to where it is mounted. From the information you posted it sounds like a continuity ground concern? But this is purely a guess on my part with what you posted so far.

 

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