A sensor device (10) for making at least one determination regarding a selected characteristic of a fluid includes a support post (32) that is adapted to be exposed to the fluid. A capacitor has electrodes (66, 68) that are supported near one end of the support post (32). A housing (40) for containing electronics (120) is supported near an opposite end of the support post (32). In a disclosed arrangement, a level sensing element such as a conductive polymer rod is at least partially supported by the support post (32). A disclosed assembly procedure includes overmolding portions of the device onto other portions to provide stable and secure connections between the various portions of the assembly.