Help wiring defrost switch!

Hi guys,
I'm installing some heating elements to heat my mirrors. I've got my wiring pretty much all set up -- running the power from the battery to a relay, tapped into the defrost signal from the existing climate controls to the control the other side of the relay, etc. but I want to put a switch in between the climate control signal and the relay so i can manually override.

I bought an OEM Toyota defroster switch out of a 1994 4Runner and it has 5 wires coming out of the back. The guy I bought it from knows nothing about it, so I'm a bit in the dark as to which wire is which.

Here's what I've got (pic below). Any suggestions/tips? Thanks!



For reference, the front of the switch looks like this. So the little defrost icon lights up when you turn on the headlights/instrument lights and the led on the top turns on when you have the heating elements on.