96 Cutlass Supreme, possible short?

I have a 1996 Cutlass Supreme and it seems to have some sort of a short or something. My brake lights work, and my turn signals work, but they won't work at the same time. For example, if I use my brakes and put on the left turn signal, the right brake light goes off. And if I use my brakes and then put on the right turn signal, the left brake light goes off. But either way, the light in the back window still works. Has anyone else ever heard of this? Please help, this keeps getting me pulled over!

Sounds like a bad signal switch also check the lite sockets and grounds to the sockets, make sure the bulbs are in right, then back to the signal switch, 3rd lite is a seperate cicuit.

i have the exact same problem. still havent figured it out, though i havent been pulled over...yet lol. i've heard people talk about the turn signal switches in these cars before, so i'm guessing that is the problem. apparently they are prone to problems.

I am currently having the same problem on my 95 Cutlass although it works just fine when signaling to the right. I am going to check the flasher. It seems to me that mine started acting up when my flasher gave me problems and I had to replace it.