Problmea rear pilots Seat Ibiza 6L

Good ... I have a problem with the rear pilots of a Seat Ibiza of 2005.
On the right pilot only the position lights and the light of progress are turned on ... and in the left pilot only the light of brake ... the rest is nothing ... good the intermittent work they work in both ... the bulbs are fine and even though I change the changes still still ... what can happen to you?

You must check with a test lamp if positive current reaches them if it does not be damaged, the cables can be sulfatado the connector or the plate or the cable harnes, finally if nothing works you can bridge a side with the other so that everything works, difficult to be fuse if only the traceras and not the front positions that do not work for you, also check the ground cable to see what happens.