dash lights problem

[paranoid]

i,ve a 1998 c250td been stood for 6 months .when the car is running ,the washer bottle and low coolant lights are on .if i go over a bump sometimes they go out for a split second.i,ve cleaned the earths in the engine bay and checked for bad connections on the dash panel all seem o.k. is there somewhere else i should check

 

[NW_Merc]

Maybe see if the bulbs are seated properly?

 

[paranoid]

but why would they stay on ?

 

[Dec]

On my car there is a float chamber that activates the empty washer fluid warning light, I recall reading somewhere that the washer and coolant lights are linked together on the same circuit so a faulty float switch in one would cause the other to stay on as well.

Perhaps your washer bottle float is sticking, try removing and cleaning.

Dec

 

[KillerHERTZ]

Yeah, have you actually cleaned the sensors inside the bottle?

 

[paranoid]

well removed sensor from washer bottle and gave it a shake to make sure it moves ,and it sounded like it did.checked the lights while the sensor was disconnected and the light was on .so i disconnected the header tank sensor aswell ,the lights stayed on ,so i bridged both sets of terminals on both items still on .cleaned earths .so do i have to take the sensors apart and if so what am i looking for?does this apply to the header tank aswell?

 

[Dec]

The only thing that will turn on the light (other than a wiring fault or a jammed float) is if there is insufficient fluid in the radiator and in the washer tank.
If the fluid level is too low, the float in the sensor will drop down and will cause the warning light to come on.

Are you sure the radiator is toped up, if it were at a low level it could also cause the washer light to come on as a double warning.
Did you wait the required 30 seconds after ignition is turned on to see if the washer and radiator light went out?

Disconnecting the sensor will not turn on the light, this applies to both sensors.
Bridging the sensor will turn on the light, this also applies to both sensors.

What I think may be happening here is that because the car wasn’t used for 6 months, the float in the radiator is jammed causing the light to think that the fluid level is low when in fact, the level is correct, in other words you are getting a false warning.

If the car isn’t overheating and the washer level is OK then I would ignore both warning lights for a while to see if the float, if stuck, will free itself… that’s what I would do anyway but would keep a very close eye on the fluid level for a while.

Dec