W124 headlamp wash wipe

[MB250TD]

Car: W124 300D estate (1995). When I turn on my lights, the washer sprays onto the headlight, emptying my washer reservoir, even though washer on stalk not pressed. Does anyone know what is wrong? Fuses etc all ok. Have had to unplug headlamp washer pump on reservoir, and connections to offside wiper motor to kill the system. Thanks.
John

 

[grober]

Earth problems

Possible earthing problem at the headlight area? Check all earthing leads for that area. Normally brown wires. If earth leads for all these components share a common connection then poor earth connection to the body could possible back feed power to the units you mention. use a multimeter to check continuity/resistance of headlight earth lead to body with headlight multi plug disconnected.Resistance should be negligible. If your not happy with electrics get a good auto electrician to check for you. the other headlight is the same.

 

[MB250TD]

Graeme, many thanks for quick reply. I cannot find an earth in the position shown in the diagram. It seems the brown wires go to the bodywork surrounding the suspension strut upper mounting on the near side of the vehicle. Other suggestions I have had are a failed relay, failed wash wipe motor, seized wiper and faulty control stalk! Relay seems OK. Wash wipe motors disassembled and cleaned (were wet). One wiper spindle was seized in shaft, and this has been released. Finally, when turning sharply, the main windscreen wiper does occasionally wipe, suggesting a potentially faulty stalk. Any further ideas/tests anyone?
Thanks
John

 

[grober]

Mb illustration pre facelift in 93??

Sorry ABOUT THAT. After reading your post I tried to find the earth connection as per the official MB workshop manual as illustrated. THEY MUST HAVE MOVED IT AFTER THE FACELIFT I too have a 1995 w124. Earth wires may well be those on the suspension strut mounting but dont know. There are 3 bolt connections as I recall. Although high up away from road salt etc these can corrode thro electrolytic action. I cleaned mine up retorqued the bolts and washers and gave them a protective cover of zinc primer. Simple to do and might solve the problem. If you have long enough test leads on your multimeter you could try removing each earthing connection bolt in turn and test if any of them is connected to the headlight earth leads. I have also scanned a couple of extracts from the manual on the headlight wash wipe circuit but dont know if they are for 95 model or not

 

[MB250TD]

Thanks for the advice and additional images. I checked earths today, used switch cleaner spray on a electrical contacts from fuses, relays to light and washer plugs. Spray even comes on when lights are on but relay removed. After all my trials: flat battery! I seem to get a flat battery even when all lights are off when bonnet or anything else open. I think alarm must draw current even when not on under such circumstances - but this is another problem. I am at a total loss as to what is going on!! Now got problem of resetting Scorpion alarm following battery charging which seems a hit and miss trial by error affair if I remember from the last time. I think that I will have to replace washer wiper motors below headlights, since these seem to be source of contacts for washer as well as wiper operation (as described in your manual guide). Anyone any more suggestions!
John

 

[MB250TD]

Headlamp wipe / blower

Well, replaced both wash wipe motors below headlights with salvage ones from Dronesfields. Turned on lights (not wipe washer at this stage), and number 3 fuse blew, after a quick squirt of water! The motors and squirt should not happen until wash wipe activated, so clearly I still have a problem. Can somebody please help!!! I have used up my supply of fuses!

Unrelated (I hope), the blower is also operating intermittently. It works fine some times and fails to come on at other times. Some times it comes on several minutes after car has been running. The only pattern I can detect is that it often does not run if engine is hot from a previous run. The left hand dial on the centre console works fine. Looking back through the car's service record, it was replaced 2 years ago at a cost of £161.56 parts and £80 labour (exc Vat) at 94,000 miles (cost of total job £283.83 at an Independent MB Specialist). The car has now done 130,000 miles.
Any body any ideas what might be wrong? I have checked previous threads, and seen something about fuse holder expansion. The relevant fuse seems to be a 10amp blade in a neat clear plastic box under a plastic black cover with some relays behind the plastic cover behind the battery, but I cannot see anything wrong with it or its holder.
Suggestions welcomed!
John