98 Malibu Reverse lights out

Okay well my reverse lights are not working. I replaced them a while ago and they did work for maybe a week, the bulbs wernt burned out though. The new ones are still good, and when i bought my car used i didnt get an owners manual. Can someone tell me what fuse(s) to check on my car please. If anyone has had this happen and it wasn't the fuses, then what happened and how did you fix

Fuse for back-up lights is in the underhood electrical center. It is a 10 Amp fuse. If the electrical center on your vehicle has a cover you will see a label numbering all the fuses/relays. Back-up Lamp is fuse #42. I doubt fuse is blown because lamps started working the first time for you without changing the fuse.

Since you got the lamps to work after trying to replacing the bulbs I would also be suspicious of how good of retention you have between the bulb and the socket it is plugging into. Maybe you should remove one of the lamp assemblies, pop out the bulb "carrier" assembly, turn the ignition ON (don't start!), put vehicle in reverse (level ground) and wiggle the back-up bulb and see if it comes on or not.

If it does I don't know if it is possible to adjust the terminals in socket to get a tighter fit to the bulb without damaging something.