A HIGH TEMPERATUE WARNING SWITCH FOR ENGINE COOLING SYSTEMS IS CONCEIVED WHICH PROVIDES WARNING AT A RELATIVELY LOWER TEMPERATURE LEVEL (E.

A HIGH TEMPERATUE WARNING SWITCH FOR ENGINE COOLING SYSTEMS IS CONCEIVED WHICH PROVIDES WARNING AT A RELATIVELY LOWER TEMPERATURE LEVEL (E.G. 212 DEGREE FAHRENHEIT) IF THE SYSTEM PRESSURE IS BELOW 7 PSIG AND AT A HIGHER TEMPERATURE LEVEL (E.G. 225 DEGREES FAHRENGEIT) IF THE SYSTEM PRESSURE IS ABOVE 7 PSIG. IN THE EVENT OF COOLING SYSTEM PRESSURE LOSS, THIS DUAL-LEVEL, PRESSURE DEPENDENT WARNING SWITCH PROVIDES PROTECTION NOT AFFORDED BY PRESENT SINGLE LEVEL HIGH TEMPERATURE SWITCHES. THE CONCEIVED DEVICE CONSISTS OF A DUAL-LEVEL TEMPERATURE SWITCH WITH A PRESSURE SWITCH INTERLOCK INCORPORATED IN THE LOWER LEVEL TEMPERTURE SWITCH CIRCUIT. IT IS CONFIGURED EVAIVALENT TO THAT OF MIL-S-12285/1 ENGINE MOUNTED TEMPERATURE SWITCHES. IT HAS SINGLE TERMINAL AND IS THUS A READY REPLACEMENT FOR EXISTING SINGLE-LEVEL TEMPERATURE WARNING SWITCHES.