Attention. Do not open the radiator cap on a hot engine. The coolant is under pressure and may spill out. After the coolant has cooled down. cover the lid with a cloth and slowly open it.
Be sure to bleed air after installing the thermal switch (see below).
1. Remove the thermal switch from the thermostat housing.
2. Dip the sensing part of the thermal switch in water.
Lower so that the threaded section is submerged in water.
3. Gradually heat up the water and measure the conductivity between pins A and B.