My 2005 PT Cruiser won't start. I turn the key and can hear low hum for 2-3 seconds but nothing else?

I see in your question that you had the battery checked did you also have charging system checked. Could be a bad alternator should be charging at 14 volts.

That checked out fine as well.

I have heard a lot of complaints of this happening to this vehicle should be but there is no recall for thi problem.

Only thing I can recommend is something you have most likely tried already that is remove and clean positive and negative battery terminals and check connections to starter making sure they are nice and tight.

The humming noise can you tell about were you think the humming is coming from ?

Not sure where the humming is. It last 2-3 seconds just after turning the key to start the engine. There is no "clicking" sound. Will re-visit the battery cables and connections just to make sure. Thanks for your help.

I would think the humming noise is the fuel pump running briefly.

Check the battery cable connections at the battery and check the connections at the starter.

So, removed the battery cables checked to make sure they are clean again. Got every last bit of corrosion off of the posts and the cables. Btw the battery is only a year old. This took about 10 min. Replaced everything and it started took it for a drive about 5 miles. Turned the engine off waited a couple of minutes and tried to start it again and it started right up. Still not sure what the problem is. Will try to get through the weekend and get it to a mechanic after the holiday. Cars only seem to breakdown when you need to go to work or on a holiday weekend.

Ok keep us informed.

So got the car to a mechanic and the problem is the ignition. Easy fix.

Does the car start when you let it sit for about five to ten minuets some times longer rite, the ground to your starter is not making contact the problem is in the black fuse box. I had the same problem run a ground wire from the fuse box ground to the starter . .car starts all the time now. Hint from John San Gabriel ca,

I’m having the same problem, mine is shut down right now. Stop cranking last Thursday, crank Friday and hasn’t crank since. And I’ve done all of the above

My experience with PT Cruisers (PTC) is that you can expect problems with the ignition as they age. The problems are the same or similar to those described in this thread. Sometimes changing the ignition solves the problem. Sometimes not. I know of one PTC sitting at a dealership, being used for parts because many hours of diagnosis and attempted repair - including a new ignition - failed.

did everything above, still wont start

I had the security key issue in my cruiser, would start sometimes, not others with no rhyme or reason. Finally got to a point wouldn't start at all anymore. $6 fix was to run a 2 wire from each side of the starter to a push button on the dash. Turn the key like you want to start the car push the button and the starter fires up. Not the most glamorous fix but the reality is these are dispose a cars at this point with literally no value left in them. A cheap fix to keep it going is far better than trying a $300+ dollar computer replacement that probably qont work anyways.