1996 Ford Taurus won't start

I have a 1996 Ford Taurus GL with a 3.0 Liter V6 and an automatic transmission. The mileage is 159000 miles. I had the engine block replaced at 138000 because of a cracked head gasket. The car has run great since then, except for it recently having trouble turning over. I switched out the battery which was two years old. That seemed to fix it for a while. Then the problem disappeared all together. I went out to start my car, but now it suddenly does not even turn over. I know it is not the battery. All my lights, instruments, and radio come on and my headlights do not dim when I attempt to turn it over. It just makes a subtle click. The car had a remote start installed, but it has never worked since I bought it. Could this be causing the problem? Also, the ignition switch will randomly ding if it is not turn in the perfect position. It is as if the key is still in the car. This leads me to believe that it may be the ignition switch. And another note: the check engine soon light is on and the code check says the catalytic converter needs to be replaced. I’m working on getting that fixed. Anyway, I would normally take it in to get it trouble-shot, but it will not start, even on a jump. I hope you have a simple solution, even if it’s just one to replace a simple part or one to get it running so that I can get it a repair shop. Thanks in advance for your insight.

The car had a remote start installed
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the ignition switch will randomly ding if it is not turn in the perfect position.
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Both of these are important. However I suggest that you start with the ignition switch. I believe that is most likely in this case, but those remote starters, especially after market ones, can be trouble and this is the kind of trouble they cause.

I suggest the ignition switch first because removing the remote starter may not be as straight forward as it appears.

Great job of providing the needed information.

You need to have someone check voltage at the starter solenoid wire to ground at the same time someone turns the key to start position. If there is twelve volts when the key is turned in the start position then the starter solenoid is bad. If no voltage is present then check the starter relay, ignition switch, and remote starter.
Good Luck