Ok the monsoon I think has more then one bulb.
Its easy to look and see, just pull it out like you did before.
Right on the back side of the display, thier should be a metal box type thing... it should have 1-3 plastic things with a screw head on them.
Make sure you either disconnect the plugs on the stereo or disconnect the battery BEFORE you screw them with a metal screwdriver, if you dont you could short something out
I thought thier might be something close in the Grand am forums with a pic of the stereo bulb too... I'll see......
Ok if the back of your radio looks like this...

Then it could be a bad display(burnt out) or it might be a bulb...
Take the screws off the top part and see if thiers bulbs on the back of the display..
Displays on these models do burn out and require dealer repairs from what I've heard.
I dont do many stock radio installs or repairs...
Good Luck