Which light can be switched from two different locations?
I'm guessing that the red/black is for one light - the red probably permantly live & will go into the common/live terminal, the black - a switch wire which would go into L1.
The other cable, is it definately red/black/yellow or red/blue/yellow?( is the yellow actually green/yellow? "Earth")
If this is the case, then it is probably as above; alternatively,
If this is the two way switch, then the red is probably live(common) & blue/yellow will go into L1/L2.
if you check the other switch you will see which colour is in L1/L2 & should be fitted to correspond. If the two way turns on at one side but not at the other then it is likely the colours in L1/L2 are the wrong way round and need swopping over.
Hope this helps!!
Ventris the Volt.
November 2006