Garage Door Transmitter

Did a search here and came up empty... can't program universal remote on ceiling of my '96. Following directions...
Hold end of remote up to universal remote and press the button on the remote and the button on the ceiling unit until red light flashes.

Red light flashes but it won't work my door.

Erased all previous codes by holding down two outside buttons until light blinks. Then tried programming transmitter again. Light blinks when programming but it won't open my door. Flipped door transmitter end-for-end and tried programming but no luck.

The one in my '98 worked fine. Would love to use this one too.

Either the owners manual or the service manual warns that the Homelink (the remote in the car) won't accept certain kinds of garage door codes. I don't recall what kind.

I think there was a lower line ceiling console trim for the Gen 8 Riviera, it consisted of a compartment in which you could place a garage door opener, with button extensions such that when you close the compartment up you could push a button and actuate the remote you had put in the compartment. Get any color and paint it to match your car with interior paint mixed at a paint store and put into a rattle can for you.