Unwanted current thru transistor
What can be the problem ?


With SW1 open, the path for Q2 emitter-base current is through R2, D1 and R3.


  Any ideas on how can I fix it ?




The above circuit uses one less transistor but consumes more than twice as much power when L1 is on than when L2 is on.  It would be straightforward to add another transistor and resistor to "fix" that.  The value of R3 should be determined experimentally.