I ordered and installed the following:
VDO 323-478 - 1/2-14 NPT - Single Channel - Floating Ground Ground 250F / 120C Temperature Sender
It works fine but, it doesn't support an over-temperature warning alarm.
The unit below reads temperature and grounds-out the alarm lug when the temperature exceeds 205°F.
VDO 323-098 - 1/2-14 NPT - Spade - 205F+/-5F - Single Channel 250F / 120C Temperature Sender
Since 'grounding of the alarm lug' is exactly how the Cummins 4BT low oil pressure alarm works, we can connect the over-temp lug to this circuit. Now the low oil pressure alarm will also sound when the engine's cooling water goes over temperature.
