wiper - Tailgate wash/wipe failure

[graham fawkner]

my w124 200TE will not wash when 'wash/wipe' is selected for the tailgate.Wipe is normal. Also selection of 'intermittent wipe' results in a two-part sweep with a pause after about 2/3rds of sweep completed. Pump. wiper leads and switches all check ok. Intermittent relay changed but same problem. Do I have to change the wiper motor or is there some simple explanation?

 

[graham fawkner]

wiper

I have resolved the problem. Yesterday I obtained a nearly new motor from a breaker (£60 as opposed to the main dealer price of £160). Hey-presto everything works and I now have the old motor to work on. There would appear to be a break down of contacts inside the motor which accounts for its bizarre behaviour and may well be repairable. Incidentally taking the car to the main dealer resulted in the usual suggestion that I change this and change that regardless of logic until eventually they would have rebuilt the car!

 

[Roger]

wiper

Thanks Graham for telling us the problem and the solution.  That was an interesting one.  I do agree with you that so many garages know little about electrics - when they need to know a great amount.  Haynes do a good book on vehicle electrics.

Roger

 

[graham fawkner]

wiper

Have now had time to dismantle the old wiper mechanism. Water ingress, probably from the shaft and confirmed by the milky grease packing, had resulted in severe corrosion of the sheet steel segmented "commutator",  shorting three of the four sprung contacts. A replacement commutator could be cut but after cleaning and reassembly I find I now have a serviceable spare rear wiper mechanism. Can anyone suggest avoidance of a repetition of the water ingress?

Also I have another water problem. The wells below the front carpet foam fillers are very wet. I have checked floor,door seals and sun-roof drains and am now beginning to suspect the integrity of the windscreen seal. Has anyone had this problem and found the solution?

 

[Mark Norton]

wiper

The area under the battery will probably be corroded, take all carpet and backing from under passenger footwell till you come across a bulkhead ledge, that collects water, and you should now be able to see the sky thru it - fibreglass or weld according to your budget/skills.  Alternatively - you may have the dreaded sunroof chassis rot - the corner pipes disintegrate with rust - very awkward repair unless you pay someone else to do it, of course.

 

[jim downie]

wiper

Graham.
I had exactly your problem, but it wasn't the windscreen.  Sun roof was the major cause, OSR drain pipe rotten, fidgity but possible to repair with patience.  Also check side estate windows both mine were leaking and the tailgate widow had corrosion on the aperture "blowing" the seal out allowing water in.  It's amazing how far water travels, I still park nose uphill and I have'nt found the cause of the water ingress to the tailgate stainless plate depression containing the tailgate lock anchor.  Still Summer's on its way.