The condition for the test is the serviceability of the thermostat and the outlet valve on the cover of the expansion tank. If these parts are defective, then the thermal switch does not work because it does not heat up.
1. Disconnect plug 1 from thermal switch 2 and bridge both contacts of the plug with a piece of wire 3 (see illustration).
4.1 Disconnect plug 1 from thermal switch 2 and bridge both contacts of the plug with a piece of wire 3
2. Turn on the ignition. If in this case the electric fan starts to work, replace the thermal switch.
If not, check the contacts and fit of the plug, as well as the condition of the power and relay wires, referring to the electrical diagram.
3. Install a new thermal switch with a new O-ring and check its operation. To do this, warm up the engine and leave it to idle until the fan turns on.