1996 c1500 brake lights .......please help!!!!!!!!

my brake lights went out on my 1996 c1500 all my other lights work except for some reason i cant get the right side turn signal bulb to stay in. i have bought a new circuit board and still have that problem. checked my brake switch....good.... all wires under the truck are bundled up look like they are in good condition. please help i need to get this working so i can hook up my trailer for my boat but i got to get this problem fixed before i hook that up. oh one more thing. none of this was going on until i tried to hook up a connector for my trailer lights on the truck. i have 6 wires under the truck that are hanging bare if that helps. they are yellow, light green, dark green,brown, (((((a big white one and a big black one, those are both connected to the frame like a ground or something))))).....please help me....

Things to check:

1. Stop/Haz fuse #1 20a in the I/P fuse block.
2. Maxi-Fuse #2 30a in the underhood fuse block.
3. Stoplamp relay in the underhood fuse block.
4. Do the rear turn signals both work?

the hazard fuse is good. usually when everything worked right when i use my hazards and i hit the brakes the hazards would not flash but stay on. i used them today and when i hit the brake they didnt stop flashing...thought that was kind of odd. also yes both of the turn signals work, but the right side has a loose bulb and i can take the lens off and push it back in and it works fine. just after i tried hooking up my trailer lights has this brake light thing become an issue.how do i check the other relay and fuse?

anyone out there that can help....? please help!!!!!!!!1

hey just went out there and checked that 30 amp maxi fuse and it was blown to bits. r/r awesome now i can tow my boat with now worries...thank you sooooooo much