1980 Chevy C-10

Not sure where my problem lays...But it seems all my lights work except for my rear drivers brake and turn signal...Ive tested at bulb and firewall with no power in either spot..... Changed fuse and relay(well one that i think is relay... Round with two prongs.... This one has me stumped.... Any help would be great....

So the passenger turn and stop lights work, right?

That tells me that chances are, the cab wiring is okay.
Use a test light and test the wires going into the light socket for power, then work your way forward, under the truck until you find the problem. Chances are, its either a defective light socket or a broken wire.

Ok,I've tested wire from bulb to firewall in several locations and still no power.... I was told that my turn signal switch may be going bad,but what would that have to do with my brake light not working on one side...... I have tried everything that i can think of...I am pulling fuse box off today to see if maybe connection is lost there .. If you have any other ideas what i might can do,please post and ill keep a update on what i find when i try the fuse box.

Ok,I've tested wire from bulb to firewall in several locations and still no power.... I was told that my turn signal switch may be going bad,but what would that have to do with my brake light not working on one side...... I have tried everything that i can think of...I am pulling fuse box off today to see if maybe connection is lost there .. If you have any other ideas what i might can do,please post and ill keep a update on what i find when i try the fuse box.

The brake light splits in turn signal switch.
Like brake on one side and turn signal on other.

Check wiring out of turn signal for turn signals on left and right rear .
If working right then check with brake on for rear brake lights.
If both rear brake lights then try it with siggnals on left and right side.
Tell us how that does.

I agree that it could be the turn signal switch or the wiring connections at the switch. Try this: Have someone watch the left brakelight while you sit in cab with foot on brake, and wiggle/apply pressure in both directions to turn signal lever. I had an older full-size truck that would occasionally exhibit same symptoms you are seeing, and in my case, just lifting upward slightly on the lever would "fix" the problem, (dirty or worn contacts in the switch). Replaced switch, problem solved. Let us know how you progress...

sorry i havent posted updates the last two days,but i am dropping truck off in morning to the shop..... hopefull they can inform me of my problem.... i will post as soon as i find out,which in turn may help someone in future....