Index level probes
Coolant Level and Water-in-Fuel Probes
Passive probes that signal low coolant or water in the fuel to the dashboard or engine computer, so the driver is warned before the engine is damaged.

- −40 to 125 °Coperating range
- 1 or 2 pinversions
- 3standard fittings
Why Index probes
Reliable Warnings
Fewer False Alarms
Low coolant probes eliminate engine failures from faulty level signals.
Diagnostics
Two-pin probes can include an internal diagnostic resistor.
Tested
Proven for long life in coolant.
Equivalents
Replacements for Medallion and Kysor probes.
The range
The Probes
Low Coolant Level Probes
One-pin (case ground) and two-pin probes with a threaded post and nut.
- 1/4" NPT, 3/8" NPT, 9/16" UNF
Water-in-Fuel Probes
Detect water in diesel fuel and signal the dash or ECM.
- Deutsch connector
Probes are passive and need an external module. For a stand-alone sensor with its own digital output, see Index level sensors.
Literature & related
More Information
- Probe and A/C part lists
Liquid level probes, APAds and ACX-10 part numbers · PDF, 9.0 MB - Index product catalogue
Sensors, switches, probes and controls, with OEM cross-references · PDF, 9.0 MB
Not Sure Which One You Need?
Tell us about the job – the machine, the conditions and what it has to do – and we’ll help you choose the right Index Sensors & Controls product.