I have a 1990 LE that did not come with courtesy lights, only reflectors. It has the cut outs an the place for the socket to go, but now actual socket and wiring.
Which trims came with the lights? Besides a junkyard, where (if possible) can I find a new kit?Am I wasting my time anyway?
That's a great project to take on. Adding those small touches to an older car can make a big difference, and you're right to think that the wiring is probably a lot of the battle. To answer your questions, the higher-end trims of the 1990 Pontiac Grand Prix, such as the SE and the STE, came with the courtesy lights. The LE was a more basic trim, which is why it only had the reflectors.
As for finding a new kit, that's where things get tricky. A brand new kit, with the light sockets, bulbs, and wiring harness, is not something you're likely to find anymore. The Grand Prix of that era is old enough that these parts are no longer manufactured. However, you're not wasting your time at all. You can still complete this project with a little bit of creativity. Your best bet is to go to an auto salvage yard and find a Grand Prix from the same year and model as yours, but in an SE or STE trim. You can then carefully remove the light sockets and the wiring from the donor car.
A good salvage yard will have the tools and resources to help you, and you can get the parts you need for a very reasonable price. You can also try searching online for used parts from a car parts dismantler. You can also try a custom solution. You can purchase universal light sockets and wire them into the courtesy light circuit in your car. This would be a bit more work, but it would give you the same result.
The project is definitely doable, and you can get the lights working. The best way to do it is to get the parts you need from a donor car.
