Radiator Fan Switch

indiemike

ZOOMZOOM
Apr 12, 2010
130
0
Wirral
My fans will not kick in when engine is upto temperature, they will only run when the a/c is running. Bought a new radiator switch, will be changing tomorrow.

Any tips or is it just a straight forward swap

Cheers Mikey
 

Nautilus

Active Member
Dec 9, 2006
547
2
Bucharest, Romania
Fan switch may also run, but react too slowly.

In my car it should trigger low speed at 96-98°C and stop it at 90-92°C, trigger the high speed at 105-108°C and stop it at 100-102°C. At least this is how it did on Torque testing, factory manuals may quote lower temp limits. Needle on the dash gauge stays in the middle as long as temp is between 85-105°C.

A few times it left the temp to creep towards 108-110°C before triggering the fans during tickover in stop and go traffic, winter temps. During moderate speed run, temps go back to 90-93°C by themselves. Fans run constantly low speed with A/C on, constantly high speed with A/C on and high coolant temps.

This means the switch fires up the fans, but too late. It will be replaced either when it fails to keep cool, or during the next oil change.