'93 Buick cooling fan relay

Our '93 Buick Century 3.3 liter overheats and the fan never runs. I did replace the thermostat. When I jumpered the fan it ran. The sensor is new. I don't know which one of the four relays up front is for the fan. The manual from the part store doesn't give a test procedure for the relays.

Any ideas? I'd rather not replace parts that I don't need. Does anyone have the test procedure for the relays? I don't know which pins to test or what they should read if I did.

Any other suggestions?

Check the part numbers on those relays. I have seen several times where they would have 3 or 4 lined up and they were all th same part number. SOOOO, you can swap them around to find the bad one. I have only seen this on GM cars. Good luck.