no brake lights

All other lights work.No brake lights either side.Also,when lock/unlock pressed on ignition key-only lights that come on at rear is backup lights. I pulled fuse cover in trunk.Cavity 15 (brake lamp 5.7L) empty! Cavity 19 had good red 10 amp. Installed new 20 amp yellow in Cavity 15-still no brake lights. Also, there is black square relays/switches in spaces 24,45,46 that dont even appear in owners manual! ( They were warm to touch so I know they have some purpose. I installed a new relay in Cavity 45-no lights still.I took car to mech at local mufflerman where I have had service before.They checked fuses front and rear with meter-they said all okay.The mechanic noticed there was not bottom metal contact in Cavity 15 to begin with(I dont know why Chrysler gives you a owners manual that is inaccurate and incomplete. The mechanic suggested I could replace the brake switch under pedal for $55. I called dealer to find out about this"stop lamp inhibit relay( I saw a website that stated failure of this relay would cause all 3 lights to fail. I called dealership,they said their software only shows the relay in front and back,but not their function. How can that be.This should not be this difficult to diagnose.I made an appointment to have my car put on their machine at dealership-$100 which they apply to repair bill. I didnt go back to mechanic to have the brake light switch replaced. It was simply a replace and see if it fixes the problem,I chose not to guess. How likely do you think it is switch not relay? How about bulbs? The mech didnt pull off cover in trunk because He said he could see the filaments-which he said were okay. Are brake lamp filaments and running light filament in same bulb? Do you have links to accurate diagrams that show what relay goes where? Thank you very much for your help!

PLEASE HELP!!! Thank you very much!