I have only one fan not coming on. Should they both come on on low with the a/c? I’m assuming the fan is bad but could it be a bad fuse or relay if it’s just the one?

 

Yes, could be faulty fan, relay, sensor, etc.

On something like a 20 minute drive with AC on, does fan #2 come on ???

 

well i let the car cool down completely. Went outside turned it on and neither fan was on. Turned on the a/c and both turned on. Temperature was holding steady. Later I was in a drive thru and the temperature gauge started rising above normal. I pulled over and the right fan was off even though the other fan was going. I had the a/c on at the time and the temperature was about 90 degrees outside.

 

I'd check for power to the fan motor when hot. Motor or relay can drop out after heating up. This way you know where to look.