[89IROC&RS]

i would assume it would be on the dimmer circuit, i can look into that tomorrow for you if i remember. i think its a yellow or tan wire for that. but im not sure. best way to test is with the plug in the back of the cluster, but with the cluster hangin out, use a testlight to back probe each terminal. and turn the dimmer back and forth, when you probe a wire that dims the test light bulb up and down with the dimmer, thats the one you want to use.