The clutch reservoir is located on the drivers side firewall. It has a small cap that can be a bit difficult to access because of the radiator support bar that is above it. Most likely the slave cylinder has a leak & will need to be changed. I am not sure which year they moved the slave cylinder from inside the bell housing to outside. If you are lucky, it was in '93. I know 87-92 have it inside (I have a '91). If it is inside, the trans & Xfer case & bell housing need to be removed to get at the slave cylinder- might as well change the clutch while you are in there. This is a very common problem on Jeeps.
Manual, top of transmission. Auto, inside the transmission.
reverse kills engine
Reverse light switch is probaly connected to switch on transmission check connections
have your transmission checked, you need a new one.
the reverse switch in the transmission
There's probably something wrong with the reverse gear. Have it checked by a mechanic then see how much it would cost to repair it.
If you mean the transmission itself shifts forward, it is because the transmission is suspended, so when the transmission is put in reverse gear the momentum will push the transmission forward. Now, if the car pulls forward when put in reverse, this means there is a transmission problem. This may just indicate the shift linkages need adjustment, or that the transmission has a major problem and needs repairing. Take it to a shop and have it checked.
Very possible ... best to check the wiring with a voltmeter checking for +12vdc.
Best guess, your Transmission is shot. You'll need to call a mechanic and tow it to the shop to get it checked out
It sounds like the 99 Grand Prix has slippage in the reverse band, or a stopped fluid path. Changing the transmission fluid and filter could help, if not then the transmission needs to be checked by a transmission since the band is inside of it.
You first need to have your electrical system on your transmission solenoid packs checked out to be diagnosed properly. It may be an electrical issue, or a bad solenoid pack on the transmission.
Because you are out of transmission fluid!! Been there, done that. Check your transmission fluid, it's probably very low. Add some and you should be good to go. You should still get your transmission checked out by a mechanic though, because you probably have a leak.