I'm striking out finding proper 96 V8 firebird wiring diagrams for the fan circuits. These are from the AutoZone site. It looks like a standard relay pinout. If so, I'd guess this….
With the key in 'run' for each fan:
Assuming 5&2 is the trigger circuit, one of 5&2 should be the ECM lead (ECM supplies ground when required), with the other being hot. Test for hot. You should be able to ground the trigger (ECM) side down to trigger the relay.
Assuming 1&4 is the power circuit, one should be hot and the other goes to the fan. You could jump this circuit to start the fan. These wires will be bigger gauge than the trigger circuits.
Any lt1 guys verify this?
This shows the trigger leads from the ECM as dark green and dark blue
http://econtent.autozone.com:24991/z...52800b882b.gif
If you have power at the relays and the relays are good and the fans turn on, your issue is ECM related (ECM, wires, sensors).
Best fan diagram I can find is 99 5.7L. ECM colors look to be the same:
