Windscreen washer reservoir level sensor. Ohms?

[AANDYY]

I think I have a faulty windscreen washer reservoir sensor.
I have good ground at the plug and about 5v at the plug.
I have removed the sensor and measured the resistance with a multi meter, I thought it would be a straight on and off when inverting the sensor but when in the 'full' position I'm getting about 500 ohms, is this correct? open circuit when sensor in the 'empty' position.

Ta muchly

 

[andy27168]

Hi,
Is this on a 210?
Be aware on 202's 208's and possibly 210's (i,ll check my drawings to confirm) that the washer fluid and coolant level switches are wired together in series, the wiring goes straight back to the cluster so neither cable at either switch goes to earth directly.
A fault in either switch can put either of the dash warning lights on, i.e, Washer fluid light can be on because of a faulty coolant switch and vica versa

 

[andy27168]

I can confirm the 210 is wired the same way as the 202 and 208.

 

[dickchailey]

Info on 208 attached, hope it helps.

 

[Ted]

Wow! Wheree did you get those schematics from?

 

[dickchailey]

Mercedes ewa.net, WIS. Someone may know if it is available on line by substription.
Water gets into the switch in the washer level device and it goes open circuit but that brings up the coolant low light! Unplug the connector and check the resistance with a multimeter, if I recall the level switch is about £25. On the 208 CLK it is easy to replace but on some it is in the wheel arch.

 

[Thomato]

Does anybody know if this is the same or similar wiring in a 2019 Sprinter? All our new work ones come up with a low screenwash error every time the engine is switched on. It's very annoying when doing deliveries!

 

[Diesel Benz]

Does anybody know if this is the same or similar wiring in a 2019 Sprinter? All our new work ones come up with a low screenwash error every time the engine is switched on. It's very annoying when doing deliveries!

No, both sensor wires (signal and ground) come directly from the SAM to the windshield washer level sensor (pe54.21-d-2127-97lab).

 

[Thomato]

Thank you Diesel Benz!