Testing a 1 prong Wif sensor with a multi meter

You have a picture and part number for sensor ?

Cant see any numbers 1 prong plug and this slots in filter, been told earth the metal
Cased filter housing

gsc1ugs said:

Cant see any numbers 1 prong plug and this slots in filter, been told earth the metal
Cased filter housing

Click to expand...

Please post some more pictures so we can see all sides of the device. include some dimensions.

Also make sure that the camera focus is on the device and not on the background.

Thats it on the right, like i said no earth just one prong in connection, the lead that plugs in reads 1.246 ohm ignition off

One pin in the connector means it's just a metal probe electrode.

If there is water contamination in the filter, the water would cause some conduction between the probe and filter case ground.

The only electrical test you can do is ensure the probe wire is connected to the connector pin.

If it's reading contamination when it should not, try with the probe plug disconnected?

If the fault clears when the probe is unplugged, I'd suspect a crack in the plastic near where it fits through the filter casing, that has moisture in the crack, causing a short. That would need a new probe.

If the fault still shows, the problem could be a connector with corrosion between pins or a wire worn through against some metalwork, or with cracked insulation & water or corrosion between that and some metalwork somewhere - a short or some "leakage" on the sense wire between the filter and whatever ECU it connects to?

Thanks for info, i’m goin unplug see what happens because my friends van is same slightly newer and he has no lead goin to the housing so its not testing for water, my van is still a none runner