99 Pontiac bonneville wont start. just get a humming. no crank or starter sound

When you attempt to crank it do the dash lights come on and can you hear the fuel pump humming ? Have you recently jumped off another vehicle or been jumped ? Are the connections at the battery and starter clean and tight ?

First, is the security light staying on or flashing ? You have a problem with the chip in the key or the security system if it is.
Otherwise, you need to know if you have battery power at both terminals on the starter when the key is in the start position. One possible cause is the neutral safety switch.

Sounds like a Fuel issue. Clogged Filter/Bad pump etc...

Are you gettiing power to the starter when you try to start it? If not,....more than likely its a relay or wiring issue.

What you need to do there is to turn the ignition switch on and off three times, leaving it on the third time. Leave it on for about fifteen or twenty minutes and the light should become steady. then you can start the engine. (I usually put a jumper battery on it to make sure it does not knock down the battery too far) If that fails to work, then the problem likely is in the switch or the security module.

if it wont crank over check for siezed pully i did a chev like that and the ac compressor was siezed

If you don`t have any lights on in the instrument panel then try getting a jump start.If it starts then have your battery and charging system checked.If you do have lights in the I.P.then make sure your getting power to the starter.Good luck.

did you try jumping it with another car.

It certainly could be,or the ignition switch.Do you got good ground & power connections? Are you getting power to the starter?

Is there corrosion on the battery cables under the insulation. There may be a smaller + battery wire going from the battery to the fuse block. Same for the ground. Are these cables clean and secure. If so start checking fuses and voltage.