Dimmer switch with regular switch

[tangoman]

I have two switches at each end of a hall. I wish to replace one with a dimmer. Both switches are wired as follows: red - l1, yellow - l2, blue, l3. When I install the dimmer in this manner it only works when the other - normal switch - is turned on. This is not what I want. Any suggestions?

 

[breezer]

you have wired it wrong it depends on whcih colour wire does what (some have red as common, i would was taught use yellow)

all i can suggest is to swop them around untill you get it right, but do the same at both swithes