94 GRAND AM Dimmer Module HELP! HELP!

Can anyone PLEASE! tell me where i can find the (DIMMER MODULE) it is'nt the rheostat.... I have all the lights working inside and outside the car except the all the gauges on the instrument panel don't light up ... but the instrument panel isnt bad because when direct power is put to it it lights up. We're pretty sure its the (DIMMER MODULE ) but just don't know where it is on the car! PLEASE CAN ANYONE HELP ME ????