I am new to this site but I need info on a coolong fan problem. My cooling fans come on when I turn my AC on , so I know they work. But they will not come on to cool motor down wen car is just idleing for a while. I put a new sensor in and cked the cooling fan fuse. Excactly what is the function of the cooling fan relay? I know it works when I turn on the Ac but does it also control the fans through thr sensor also?

 

Yes. Is it overtemping? If not, probably just means it dosen't need to be on.

 

yes it overtemps and I either have to puill over to let cool down or turn the AC on to make the cooling fans come on,

 

How are you electrically? I'd suggest checking the relay, The fan relay should (coil) energize when the ecm sees the temp from the sensor. The relay contacts should close to allow 12 volts to the fan motor. I suspect without seeing it relay contacts are burnt. You can either check with a voltmeter or test light, or replace the relay. Replacing the relay may not be the problem.