tail light

[loader820]

I have a problem, I have a chev C10 which my break lights, I check the turn signals and everythin i check the fuse and all the fuse are good but when i turn on the right turn signal the reverse light on the left side start to blink while the right side turn signal is on I have park lights but i dont have no brake light when could be the problem with the wiring is it the wiring in the back or is it the front where it can be the problem