I have an approximately 13 year old Hampton Bay remote controlled ceiling fan in my teenaged son's room. He has not had any lights in it for years and my wife recently requested I install them. I did so and the lights turned on as I screwed them in. The remote correctly controls the fan operation and dims and brightens the lights, but will not shut off the lights. I reprogrammed the remote to control an identical fan in another room and found it to correctly control all functions. I removed the light kit and found all wiring appears normal and undamaged. What do I need to replace? Thank you for your consideration.

The receiver.

Does the fan have pullchains?

Ceiling fan remote controls - help and FAQ- Ceiling Fans N More

No. The fan is hardwired, does not have a switch on the wall, and does not have pull chains, otherwise I would use it to turn off the lights.

I find it very odd that the remote will dim and brighten but not shut off. I'd check to make sure that you know how to use the remote, and that it is good, but you already eliminated that by trying it on another fan. So replace the receiver. You will have to order a new one from the manufacturer.