92 300e INSTRUMENT CLUSTER FAILURE

I Started The Car This Chilly Morning And Noticed All The Instruments Dead With The Engine Running Fine. There Was Also A Buzzing Noise Coming From Under The Dash. When I Drove Off, The Speedometer Was Working But The Other Indicators Remain Unresponsive. The Buzzing Noise Stops When I Turn On The Signal Light But Comes Back On As Soon As I Turn The Signal Off. Any Ideas?

check fuses for corrosion