The owner before me wired both fans to come on when the key is in 'RUN' or 'ACC', and I wanted to fix that. I bought a Hayden kit that comes with a temp probe/switch that mounts in between the radiator fins and turns on @ 185* and off at 160*. I hooked everything up and included a manual override switch. Went to test it, and the manual override works fine but the switch never kicked in. The temp gauge climbed to 220+* and nothing happened. I verified the gauge with WinALDL, and it is correct. I verified the switch works by holding a torch under it and measuring the voltage across - when heated, it closes; when cooled, it opens. I then relocated the probe/switch to a T-fitting in a radiator hose, hoping that would trigger the switch sooner, but no luck. So where is the best place to mount these things?

 

Doesn't it have a small metal dial that you can turn, like a house thermostat so you can "dial" in when you want the fans to switch on? I put my probe on the top of the bottom radiator hose.

 

No, it's not adjustable. Just a thermal switch with preset on/off points. Your probe is just sitting on top of the hose, not inside and it works fine?

 

Yeah, I didn't like it shoved in the fins of the radiator so I just zip tied it to the top of the bottom radiator hose.