What indicates an inoperable block heater when using an ohmmeter?

When determining the operability of a block heater using an ohmmeter, the correct indicator of inoperability is the presence of infinite resistance between both heater terminals. This means that no electrical continuity exists within the heating element, indicating a break or failure in the element itself. A functioning block heater should showcase low resistance and good continuity, indicating that current can flow freely, heating the engine coolant as intended.

Having continuity between both heater terminals would suggest that the element is intact and capable of carrying current. Additionally, no continuity between either terminal and ground is normal for a functional block heater, since it should be isolated from ground to prevent any leak which could lead to shorts or safety hazards. Thus, if a block heater is functional, you would not expect infinite resistance across the terminals.

The choice indicating all of the statements as potential indicators of inoperability can be misleading since only infinite resistance distinctly points towards a failed block heater element. In a functional condition, you would typically expect to see continuity between heater terminals and isolation from ground. Hence, understanding these concepts is crucial in diagnosing heating components effectively in automotive applications.