95 sonoma tail light problems

when i switch the lights on, only my head lights come on.

if i press on the brake and then let go the tail lights come on.

but when i go to use the brake to stop the tail lights go out. and then come back on after i let go of the brake.

also when i have the lights on, my tun signals dont work.

thanks for any suggestions as to what my problem is.

Classic symptom of a poor or non-existant ground for the tail lights. Could be a broken wire, or even a faulty taillight socket.