Davrosballino

Hello all, I have an interesting one. My rear fog lights don't work and boot wont open. The fog light indicator on the dash is on when I brake and/or when the head lights are on. Now, when I switch the fog lights on....the boot can be opened. I think it may be a relay but I have looked at the ones in the rear side panel but they appear to be fine. ...Now the boot has stopped opening whether the fog light switch is on or off. Any ideas? Dave