Sunroof on grand prix only works when i tap the button

SOURCE: Rear suspension of 1994 Grand Prix bad.

i have owned two 1994 grand prix's and both developed the same problem you are refering to.
i have to agree with the last solution, if the rear is sitting lower, it's time to look at your rear struts. BUT... the GM used a fibreglass monoleaf transverse spring in the rear and the fibre glass spring is suppose to sit on a nylon cushion on both knucles. on both of my vehicles i had the nylon cushion fall or get knocked out. the parts cost about $20.00cdn and can easily be installed without removong the spring. In both cases it solved the sound of metal on metal rubing sound. I also changed the rear struts soon after i replaced the cushions because i noticed they were worn.

hope it helps cheers!

SOURCE: Sunroof will not close.

it sounds like the motor is working?
maybe is a little gear that's near the lights of the roof.

check it out.

SOURCE: My front and rear power windows in my 1997 Grand

it sounds to me that the cables have broken. it requires installing new regulators. pretty easy once you get the door panels off. follow the bolts. the window is bolted through sashes to the regulator

SOURCE: 2005 grand prix -- trunk lid won't open

If you will turn the ignition on, press & hold the door lock release button to the left . . . . viola!

SOURCE: security light flashing while driving 2001 grand prix

The TDM, that is the brain of the security system (VATS/PassKey), is having problems, it's typical on those cars and it will gradually prevent the car to start anymore. You can find a great write-up here: http://newrockies.ca , this has been the only thing that saved my Park Avenue.