windshiled fluid reservoir light on, even though reservoir full - how to fix
 

My dash idiot light indicating that the windshield washer fluid reservoir was low came on the day before I was scheduled to go into the mechanic for an oil change. Since I was going in the next day, I didn't bother to fill it up. He did, but the light has not extinguished, (this is on my 190D, light always goes out on my 300CE). I didn't notice the light was still on until I left the mechanic, and he didn't have time to address it anyway since it was closing time.

Is there anything that I can "do" to make the light go out? Already tried pulling the plug and re-seating. I was planing to take a run to the pick-a-part junkyard this afternoon. Is there anything that I can pick up to replace whatever it is that is broken?

Thank you for any help you can offer.

Your low fluid sensor is probably defective. You can drain the fluid from the reservoir and take it out and clean the connections with dielectric grease to see if that will help. Looks like you can buy a new one from Fastlane for $30.

http://catalog.peachparts.com/ShopByVehicle.epc?q=1984-Mercedes--Benz-190d-Body--Electrical&yearid=1984%40%401984&makeid=63%40%40MERCEDES+BENZ%40%40X&modelid=6119%3AMBC%7C1481%3AED% 7C10000092%40%40190D&catid=241959%40%40Body+Electrical&subcatid=242438@@Washer+Level+Indicator&mode= PA

Thank you. Car being 25-years old, that's probably a good guess. I'll try cleaning it first.

Where can I purchase "dielectric grease"? Auto parts store? Any specific brand I should stick with?

I took mine out of the tank and smacked it a few times, then shook it so the float banged around a bit, put it back in, and it has not given a faulty reading for a long while. :D I collected several from the junk yard since....to play with. :D They don't charge for stuff like that so I took like 5 of them. :D

You can purchase any reputable brand of dielectric grease from auto parts stores. It is good preventive maintenance to remove electrical connections and apply a bit of grease to them, especially in the engine compartment. It will keep the moisture out preventing corrosion and electrical gremlins.

Fixed! Replaced sensor with a junkyard pull.
 

That was it! Picked up a couple from the junk yard after work. Only two cars had them, a W201 and something else (a big one). They charged me ninety-nine cents each. The one from the big Benz is shorter than the one from the 190. Cleaned up the longer one, removed the old one, put the "new" one in, and wha-la...no more light.

A cheap (I mean, inexpensive) fix. Now, I have to figure out how to fix my trunk lock. Sometimes, I can't get the trunk to open, even though everything is unlocked. Thanks again.