Chevrolet Repair: tail lights, light sockets, marker light

Question
every time i turn on my head lights the fuse blows for the tail lights 1990 astro van

Answer
Hello Pat,
It is possible that just a light bulb has come loose and the contact in the socket is touching ground.
This could also include the front marker light sockets.
Another possibility is a shorted wire, but check the bulb sockets first.
Any side marker lights are probably on the same circuit.
Van