1996 buick roadmaster taillights not working but brake lights and all other lights are coming on.I changed all fuses and headlight switch and bulbs and my tail lights are getting a circuit.I don't know what else it could be.call me at 334-356-2754 for suggestions

Can't find a diagram right off, Tail lights get power through the headlight switch. Fused tail circuit feeds through headlight switch.
I like to put a tone on the wire and follow back to headlight switch with inductive amp. May go through a security circuit, causing the lights to flash in alarm condition.
If you find a diagram online let us know.
The Service Manual should have electrical diagram. The Manual will save you time and money for as long as you have the car.