My tail lights are not working correctly. Can someone tell me which lamps are supposed to be on in the following conditions? I think this is how it's supposed to work.

headlights off, brake on: just the inners lamps?
headlights on, brake on: both inner and outer lamps?
headlights on, brake off: just the outer lamps?

Where should I start troubleshooting if all lamps are turning on, but in the wrong sequence?

 

headlights off, brake on: just the inners lamps? Outer lamps full power
headlights on, brake on: both inner and outer lamps? Outer lamps full power + inner lamps
headlights on, brake off: just the outer lamps? Outer lamps dim + inner lamps

I believe that is how it should be, but I could be wrong.

 

bump...can anyone confirm and suggest troubleshooting measures?