Main.TrailIndexPage | Engine | Thermo switch

Thermo Switch

This component is part of the Engine. Also see the related topic Fuel Injection. For a comprehensive look at how this all works together, see Engine Starting Aid Tour.


The "thermo switch" is a single terminal sensor which was used only on the earliest 230SLs and earlier sedan engines (described in the early BBB as version ll). The thermo switch was not used on any of the later versions. In fact a factory modification involved in disconnecting the thermo time switch and leaving it unhooked along with other modifications (for more info see the Engine Starting Aid Tour). It functioned by providing ground (earth) to a relay at temperatures below 113 °F (45 °C).

Thermo Switch

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