Tail lights not working 94 sonoma

If the tail light fuse is okay-the problem is coming from the headlamp switch assy-

Well i couldnt find a fuse that was just for the taillights. so would a test light work to see if the switch is going out? My head lights work when i turn on the switch

Check T/L CTSY 20amp in the I/P fuse block-and test the brown wire on the headlamp switch it should have power when you put the switch on

So what i need to do is keep the switch plugged in and take a test light and check the brown wire with the switch on? if there is not power to the brown wire what else is wrong. Ive check every fuse there is more then once and there all fine

If the switch is on and no power coming out at the brown wire the switch is defective

ok so i checked the brown wire and it works so its not in the switch, So somewhere from the switch to the light the power is getting cut off. is there a relay to the taillights? what could be between the switch and the lights that could cause the power lose?

There's no relay in between you have an open wire between the switch and bulb sockets