Why does my break light flash instead of my turn signals wjen i turn my signals on.

I think that's how they're supposed to work.

If you have separate lights for both, check to see which lights up when the brakes are applied. If they are switched in function, then the wires leading to them are switched, or it is switched at the fuse box. If you only have one bulb for both, do the brake lights come on when the signal is working? Does the signal come on when the brake light is on? If only one works, you may have either a blown bulb, incorrect bulb, crossed wires or two wires on the same post or shorting out against each other. If it is only one light that does this, make sure the correct bulb is in the socket, and check the wiring connections. If both do this, make sure the correct bulbs are in, or the wiring is crossed at the fuce box. Has there been any repairs to the lights or buse box prior to this happening? If not, check for worn or fraied wires that may be touching or have been crossed.