Tail Light Assembly 2001 Century

I noticed that my tail lights in the trunk section were not on ,along with the licence plate lights. But the lights in the quarter panels were on and working ok.I pushed the trunk button to open the trunk with the key phob and it also would not open,, that is untill the headlights timed off .
When I used the headlight switch to turn on the lights the trunk section lights did not come on and the trunk would not open untill I shut the lights off.
With the light switch pulled out I can hear the trunk relay clicking when I try to open it,but it dont open.
Also with the light switch off ,when I push the trunk button the trunk will open and the lid lights will flash.so the bulbs seem good .
I checked all the bulbs,sockets,connectors and wires and they all seem fine.If any one has the same problem and has found the answer please help
Thanks chevere

I had to read your symptoms three times to get the drift of it. I wonder if you have a grounding problem on the trunk lid. I'd expect the ground to be wired in through the wire harness, but it might be worth connecting a temporary ground from the trunk lid to the body somewhere.
Also I've seen funny things happen on some cars when a tail light or stop light bulb burns out - sometimes the other lights act abnormally due to alternative circuit paths. Maybe check all lamps with a multimeter in case one filam,ent is burned out.
Did you check the wiring harness for damage?

Thanks for the reply,,it is strange and I think it has something to do with the ground being switched through a relay,say the headlight ,or trunk relay.I think this because when the lights are on weather it be with the switch or the sensor the trunk will not open ,which makes me think if the lighting relay is enegerized it opens the ground for this circuit or something.I checked all the harnises ,plugs,and lamps and they seem fine.Do you know where the lighting relay is?

I had to read your symptoms three times to get the drift of it. I wonder if you have a grounding problem on the trunk lid. I'd expect the ground to be wired in through the wire harness, but it might be worth connecting a temporary ground from the trunk lid to the body somewhere.
Also I've seen funny things happen on some cars when a tail light or stop light bulb burns out - sometimes the other lights act abnormally due to alternative circuit paths. Maybe check all lamps with a multimeter in case one filam,ent is burned out.
Did you check the wiring harness for damage?