No A/C. Cooling fans do not turn on with A/C. Chevy Uplander.

I'm trying to figure out why my A/C blows warm air. I made sure my refrigerant was charged. The clutch is engaged and seems to be spinning well. However, the cooling fans aren't activated when the A/C is turned on.

I tested the fans by connecting jumper wires and they did operate at normal speed. After jumping them, I plugged them back in and they kicked into high for a few seconds before completely stopping. I removed the relay and plugged it back in and the fans began to spin for a few seconds at "normal" speed before stopping after a few seconds. However, I wasn't able to duplicate this by trying again.

I tried swapping relays from known good components and it appears all relays are working properly.

So the fan motors appear to be ok. Relay seems ok. The clutch is engaged and spinning. The refrigerant seems to not have a leak. Any guess as to what I should check from here? I'm guessing the key to figuring out why my a/c isn't cold is to figure out why the fans aren't engaging when the a/c is turned on.