What's the best way to check this "other" fan? my right side (passenger) fan comes on with the a/c, when i'm not using the a/c, the same fan comes on to cool the car down, and sometimes after i've turned my car off and it's just sitting after i've driven it... The drivers side (left) fan has never come on since i've had the car from 80K miles and I"m @ 160K now... is there an easy way to check it? Also my car has gotten pretty damn close to red a few times and it's never kicked on, so I don't think it's a "backup" fan or anything like that but i may be wrong... anyone know anymore about this?