Thermocontacts, thermostats

THERMOCONTACTS, THERMOSTATS

Thermal contacts change their condition (closed or open loop) when a certain temperature is reached: these may be N.C. (normally closed) or N.O. (normally open): on the diagrams they are shown in the resting position.

To check, remove the contact from the car and connect the terminals to the ohmmeter tester.

Use suitable equipment (vessels or containers that can be heated and cooled) check that at the set temperature, specific to each thermocontact, the resistance passes from 0 Ohm to "infinite" resistance or viceversa.

The temperature senders(thermostats) emit a signal that is directly proportioned to the temperature they find.

On the electrical diagrams they are treated as rheostats in which the resistance changes with the temperature.

For checking, follow the instructions given for rheostats, but use equipment that allows temperature variation.

PRESSURE CONTACTS, PRESSURE SWITCHES

The pressure contacts change their condition (closed or open loop) when a certain pressure is reached: these may be N.C. (normally closed) or N.O. (normally open): on the diagrams they are shown in the resting position.

To check, remove the contact from the car and connect its terminals to the ohmmeter tester.

Use suitable equipment to check that at the set pressure specific to each contact, the resistance passes from 0 Ohm to "infinite" resistance or viceversa.

The pressure senders (pressure switches) emit a signal that is directly proportioned to the pressure found.

On the electrical diagrams they are treated as rheostats in which the resistance changes with the pressure.

For checking, follow the instructions given for rheostats, but use equipment that allows pressure variation.

SENSORS

These are various types of components that detect specific values and emit a signal in proportion to them: for these a table or an electric load diagram will be given each time; following this the correct resistance or voltage values can be found that are to be checked with a tester.