1988 Pontiac Firebird Location of cooling fan temp switch

My 5 liter 1988 v8 automatic radiator fan motor does not go on- I have the 5 liter TBI engine. I replaced the cooling fan relay, coolant temperature sensor. The fuse is good in the interior and I bench tested the electric fan and it wooks good. Does this engine have a cooling fan temp switch or is it controlled by a computer chip in the ECM? If it is controlled by a chip in the ECM then I am at a loss of what to do next to make that fan go on so I can stop over heating in traffic. Appreciate your help-Thanks