Hi,

My radiator level light is permanently on.

Level in rad is fine.
Sensor resistance is correct and does change as per spec when level changes hence, is working.
I'm told that the measuring loop is a 'resistive loop' and is in series with the screen washer level sensor therefore, I have also checked that sensor out and it is also fine. I have tried replacing both sensors with the equivalant resistor - this makes no difference. Anyone any ideas??

 

your C200 is 202 or 203?

it is voltage coded and replacing it with resistor might not work.

anyway, if the coolant level is okay, it should be 110 ohms and less than 5 ohms if defective or low.

the washer fluid is okay if 174 ohm and empty or defective at less than 5 ohm.

did you use 284 ohm jumper for both and still got problem? then you may need to check the wiring.

welcome to the forum.

 

...

[IMG]local://upfiles/1/A35703A7E7AC46E5B1EE0518570B3FCE.jpg[/IMG]

 

Hello Sleepwalker,

Thanks very much for the detailed reply and the diagram.
My car is a 202.
Yes, the resistors used were 284 ohm in total - I have the same MB diagrams hence, I knew what to check for and what values to use.
I too agree that it seems to be wiring however, to trace it is going to be a pain! - Just thought I would ask before I wasted a whole day searching!

Ken


PS. Thanks for the welcome

 

but as you can see in the wiring diagram, you will go nowhere else for checking but on instrument cluster only.

quite easy...except pulling out that cluster

 

For other members who may be interested, the attached screen shots detail the function of the coolant level and washer level series loop.

[IMG]local://upfiles/9941/B661F4A99D5F41FB8E4FAB3D64B7EB09.jpg[/IMG]

[IMG]local://upfiles/9941/EB5490A1B1344ABF953AEE02002B2F70.jpg[/IMG]

[IMG]local://upfiles/9941/1E147777D1E34DE1BA16B4CC4DC4C8E5.jpg[/IMG]