Engine Cooling problem
1988 Acura Legend 6 cyl Front Wheel Drive Automatic

I have an Acura Legend 1988 LS. I was unable to pass smog because my cooling fan would not come on when the car idles and starts to over heat. i have taken the fan motor out and hooked it up to the battery and it works. i have checked the fuses and they are all good. I am wonderring if it could be the fan control swotch aor the relay. I am trynig to get the fan to work.