Installed a new battery on 1995 lexus 300 and need code for radio and locks to work

on some cars the airial for your radio are built into the rear window.

As both the radio and ventilation motor packed up simultaneously, I suspect a common 12V positive feed, so if fuses ARE ok, then try unclip fuse box as far as possible to look for a burnt off / broken terminal. As you said p-locks & p-windows didn't work before, there might be loose connections hidden away under dashboard, behind console (center).
Happy hunting!! :)
Clive.

First thing to do is look carefully in the owners manual. A good mechanic [or owner] will write the code in either the main manual or the manual for the radio. If there is no code available, go to any Lexus dealer's parts department. Be SURE to bring your auto registration with you [to prove you own the car] The parts guy will be able to look up your radio code using the VIN [vehicle identification number] listed on your registration. Usually, there is no charge for that.
Your owners manual will spell out the procedure for entering the security code [usually 4 or 5 numbers] to get the radio working again.
Charlie

The radio is probably locked out due to the antitheft system. It needs to have the security code (PIN) entered to get it working again. If you do not know the PIN. you will have to take the car to the dealer to get them to unlock it for you.

Battery was disconnected or replaced and activated the anti-theft system within the stereo. Usually the code is in the owners manual, call your lexus dealer if you are unable to locate the code!!

do you hear the starter click or try to turn the engine. Most likely it is your starter. The contactors wear over the time/the number of starts over the years. You can get a rebuilt starter or buy a new one. If you are up to the challenge you can but repair kits to rebuilt it. It a 300-400 dollar job at the dealer.

YOU WILL NEED THE RADIO CODE.. If you dont have the code you may call the dealer with your vin number, or the radio serial number. it may be in the owners manual, sometimes I write them on the owners manual in case the card gets lost, may look like a credit card.

You need a group 24F battery. A group 35 will fit, but the CCA's (cold cranking amps) are rated too low for the vehicle. There is nothing to reset other than your radio presets and your clock.

dealership will have yor code you will need your VIN number handy call a local lexus dealer ask for a radio lock code it is free by the way they will try and charge you dont let them

More often than not, the long "beeeeeeeeeep" can be traced to a door that is not closed properly, or a dome light switch for a door that is not working properly.