The battery was dead in my 91 Lexus. I had it jumped several days ago and it ran fine. Got home and tried to start next morning but it was dead. Put battery charger on the battery and it is the type that has a LCD which after trying to charge read out bad battery replace. I took the battery out and bought new battery. I put it in but the car still does not start. No lights, horn etc.

I am wondering when I removed the battery that it has some type of theft deterrent and I have to do something special for the car to "reactivate". I tried locking all the doors, hood closed and then put the key in to unlock the drivers side door. I then tried to start the car but still it is dead. I rechecked the cables and the terminals and all is on tight. Anybody out there that can give me a clue?

Wondering if the polarity is reversed or something got crossed. Do all the dash lights come on as usual? Turn key then nothing at all, not even a click sound?
Something is not making a connection. Check your underhood ALT 100A fuse near the batt. Report back.

Have your "new" battery retested, as well as rechecking the cables...
If the battery was installed correctly, the car should start.