My recirculation wont work in my 420sel. what could be the prob??
 

I was in traffic and a bus with a really smokey diesel is in front of me. I try to put my recirulation on but it doesnt even work. The button doesnt even light up. Car has only 55k miles. I check the fuses and they are good. All climate control features are operational. Could it be that the button needs replacing?? 87 420SEL