There are a few posts in here that get close to the truth, but maybe don't hit it right square on the head. Let's clear that up.
Attached are all the relevant fan tables for controlling the fans. It's important to note that the Fan Desired % vs ECT (coolant temp) table is not stock, it is modified to suit a 160*F thremostat and keep things as cool as reasonably possible.
As you'll note, the fans can be "triggered" by either engine coolant or AC pressure meeting a given threshold that translates to a desired percentage of fan speed (tables 18030 and 18031. Now, that desired percentage works when you have a nice variable speed fan - but we don't, just high and low, so it gets translated into a "state" (0,1,2) by table 18040. Then, that gets translated to turning on and off relays that run the fans on table 18045.
The relay control scheme can be confusing as well - some assume the fans are controlled independently, but that's not strictly true. In state 0, everything is off. In state 1 a single relay closes, which completes a circuit to allow current through both fans, in series, which results in the "low" fan speed. In state 2, two more relays close. The second relay breaks the series connection between the fans, and grounds the first fan. The third relay provides power to the now divorced second fan. With each fan now driven in parallel, rather than series, the speed increases and you get "high" fan speed. Sounds complicated, but the result is that you get at least 1 fan running on high if you should have a failure of a fan or a relay in the system.
So, what's going on with the OPs car running the fans when the engine coolant isn't hot? Well, it sounds like he's running the defrost, which does run the AC pump in order to dry the air for the best results in clearing the window. This creates pressure in the AC system, and as that exceeds 1,100kpa, it kicks the fans on low to bring air over the condenser. So, it sounds like it's working exactly like it should.
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Originally Posted by Mouse330
Get the A/C pressures checked, Sounds like you need a charge
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Actually, if the A/C pressure is low (needs charged) then you won't get the necessary pressure to trigger the fans at all with the AC system.
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Originally Posted by bsn
The AC clutch will cycle-that's normal the fans should be on anytime the clutch is engaged and will stay on if the engine temp is high enough. I assume on a Camaro if the engine is warm enough the fans will run with the engine off as many other cars do. I doesn't sound like you have a problem.
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Right on - I agree, it sounds like normal behavior.