on r32 its the green one with the white trace wire. bottom left hand corner of the smaller of the 2 wiring looms on the hicas computer.
dunno on R33, but get your hicas computer, pull the wiring out and then use a short piece of wire connecting each pin on the harness to its respective pin on the the computer until you find the one that turns the light on. once you've found it, cut that wire
thats what i did on R32 anyway, dont think it would've changed dramatically for R33
give it a go