my fan isnt turning on?

Hello pontiac 89 tempest-corsica clone
witch relay are witch in the engine compartment - I have four on my fire wall my coolent fans not turning on - dont no whats wrong - new motor tested new colent temp- below thermistate, and new thermistat.
any suggestions?
what senser turns on the fan

I don't know but I have a 94 corsica and mine did the same I had to change two items the temp sensor on the thermostat houseing when took a papper clip and shorted it out the fan came on. this seemed to work fine so i changed it out. but in the next week the fan was not cycleing right. so I looked at what color the wires were and tried following them around the motor till I found a bank of 4 silenoids, did not make sence to start the motor so shorted the one on the thermostat again then I started shorting the silenoid with the rite colored wires and then the fan came on so I changed it, all seems ok now. good luck to ya.

all i did was wire it to where it would turn on automatically when my car turned on. I hard wired it to the ignition basically.