How do you know if the fan relay is bad?

I’m trying to troubleshoot why the radiator fan right in front of the header is not coming on either when the cars warms up or if I have the A/C on. How do you know if the relay is good or not? TIA for your replies.


I think I have a similar problem… first of all, I would check to see if there’s voltage at the connector for the fan…(the green one on top of the fan) It could simply be a bad fan. I could also be the temp sending unit, I don’t really know how the cooling fan is working, but on my old car, it simply was a thermo-switch… and it could be the relay, which is easy to check by probing the signal… if there’s a 12V signal coming to the relay and the fan isn’t working, the relay is bad!