Page Created by T Sept 19th 2009:
Holden Cars that do not have a Dash Temperature Gauge and only have a Temperature Light use a Temperature Switch.
Note that there is no Adaptor used and the Temperature Switch screws directly into rear of the Cylinder Head on the Manifold side.
The Switch is off when the Engine is cold. The Switch only turns on when the Engine overheats. Sometimes the Temperature Switch fails when the Engine overheats and has to be replaced immediately afterwards.
EH And Later Lamp Test:
EJ & earlier do not have this feature. Dr Terry
When the Ignition Switch is turned to START, a contact inside the Ignition Switch shorts the Temperature Light to ground to test the Lamp. By Dr Terry 01/11/14@08:58 *new
The failure of the ignition switch in this area is due to people 'hot wiring' the ignition coil. In the LOCK position, the ignition coil positive is earthed out using the same contact as the temp light. When someone hot wires the coil this contact gets burned out, so the temp light checking feature is then lost. Dr Terry
Holden Cars that have a Dash Temperature Gauge use a Temperature Sender. Temperature Sender