I hooked into the wiring harness going to the radio. Can't remember the wires though. If I get a chance I'll look again, but I have to pull the stereo out.
i tapped power and ground from the dimmer switch. there is a 12v constant and ground there that is not affected by the knob. also the gauges will turn on when the cluster turns on, not when youre just listening to the radio with the engine off. you can easily push the dimmer switch out if you reach under the dash and squeeze the clip on the top and bottom. no need to disconnect the harness.
^^ thanks for the idea.. I'll have to see how this works on Proteges, our clusters only light up when the headlights are on so it might not work.. I'll do some probing around with the multimeter when I get a chance.