Help with wiring an programmable light switch

[trevsand]

Hi everyone,
Ive trying to install a Leviton Vizia switch for my outdoor lights.
I opened up the box and tried to remove the old switch but the wires are not color coded. The switch is the middle of a 3 switch panel. The switch to the right is a 3-way switch for the hallway. The switch to the left has wires connected to it but I've never known what it powers. The switch I'm trying to replace has one wire on the top screw and 2 wires on the bottom screw.
It looks like the top screw wire goes to the hot wire. Of the wires on the bottom screw, one goes to the switch on its right hand side (the 3 way switch for the hall) and the other appears to go to the ground but I'm not sure.
My new switch has 5 wires and colors - black, red, green, white and yellow.

Any help would be much appreciated.

Regards,

Trevor

[JP]

If the existing switch works, you should be able to replace it using only the existing wires connected to it. The new switch should have diagrams and most likely can be wired as a single pole or a three way switch. However you will need to use a meter to figure out which is the feed wire for the existing switch and which one goes to the light and ground so that it is wired correctly.

[trevsand]

How do you use a meter to figure out the feed?
Also once I know which is the feed wire, which colour wires would I be using and not using?

[JP]

With the wires disconnected from the switch, the one that still has power would be the feed. For the connections you will need to read the wiring diagrams that came with the switch.

[trevsand]

Thanks,
Once I know which is the hot wire, which wires would the other 2 be. They are both on the bottom screw of the switch.