1998 Sable -Dead -Won't Start

I have a 1998 Sable, not a bad car, initially had some problems with keyless entry, sometimes had to press "lock" on keyless or it wouldn't start. Now it doesn't start at all. No starter click, battery seems good, with lights on no fading when ignition is turned on, lights stay bright, no fade. Checked every fuse, nothing. However with ignition on if radio is on, it will go dead (radio), but headlights will still remain on. Computer maybe? Keyless entry problem? I did repace the battery to it. With key in ignition with accessories on all idiot light(dash) go on . When put on the start position the engine light and brake (I think) stay on everything else goes off. Again , no starter clicking, but lights, radio, windows etc. work. Battery cables are clean , ground looks fineHelp!!!!

Is the starter getting power when the key is turned to start? Is the solenoid working? Are all the connections clean and secure to the starter and the solenoid?
Using a wiring diagram, start with the starter and work your way back, checking each component.
Diagnosing electrical problems require a patient and methodical approach.
If the connections are good and you are getting power to the starter and have a good ground, the starter may be bad. Worn bushings in the starter motor can bind and not allow the starter motor to turn (tapping on the starter with a hammer can sometimes free up the starter motor).