I have a 99 blazer and the cluster guages and the thermostat is not lighting up the overhead display (temp, direction, etc.) Works when my lights are off but when i turn the ligbts on it goes out. On my cluster the warning lights (abs, service engine) still work. Ive checked the fuzes abd they are all good, i was thinking it could be the dimmer switch but i thouht i would ask for some advice.

Thanks for looking