elbow15

I have a 1991 GXE. My AC fan intermitantly turns off and on. Once it cuts on it normally stays on until I turn the car off. Once it is working I can turn my fan off and on, so I think it isn't a switch problem. I think it may be a ground or a relay, but I don't have a clue where to look. I found one relay near my heater control, but I don't know what it controls. Any ideas on what it could be? Any suggestions would be appreciated.

block

My fan cut out earlier this week for the first time. I thought the fan was dead and I was going to replace it but then it started working again. I'm really not sure but I would like to find out how to fix this problem